Di-fluoro containing compounds as cysteine protease inhibitors

ABSTRACT

The present invention is directed to compounds that are inhibitors of cysteine proteases, in particular, cathepsins B, K, L, F, and S, and are therefore useful in treating diseases mediated by these proteases. The present invention is directed to pharmaceutical compositions comprising these compounds and processes for preparing them.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a Continuation of U.S. Ser. No. 13/004,838, filedJan. 11, 2011, now U.S. Pat. No. 8,367,732, which is a Continuation ofU.S. Ser. No. 12/060,774, filed Apr. 1, 2008, now U.S. Pat. No.7,893,112, which is a Continuation in Part of U.S. Ser. No. 11/866,836,filed Oct. 3, 2007, now issued as U.S. Pat. No. 7,781,487, which claimsthe benefit of Provisional Application Ser. No. 60/849,587, filed Oct.4, 2006, each of which is incorporated herein by reference in itsentirety.

BACKGROUND OF THE INVENTION

The present invention is directed to compounds that are inhibitors ofcysteine proteases, in particular, cathepsins B, K, L, F, and S and aretherefore useful in treating diseases mediated by these proteases. Thepresent invention is also directed to pharmaceutical compositionscomprising these compounds and processes for preparing them.

Cysteine proteases represent a class of peptidases characterized by thepresence of a cysteine residue in the catalytic site of the enzyme.Cysteine proteases are associated with the normal degradation andprocessing of proteins. The aberrant activity of cysteine proteases,e.g., as a result of increased expression or enhanced activation,however, may have pathological consequences. In this regard, certaincysteine proteases are associated with a number of disease states,including arthritis, muscular dystrophy, inflammation, tumor invasion,glomerulonephritis, malaria, periodontal disease, metachromaticleukodystrophy and others. For example, increased cathepsin B levels andredistribution of the enzyme are found in tumors; thus, suggesting arole for the enzyme in tumor invasion and metastasis. In addition,aberrant cathepsin B activity is implicated in such disease states asrheumatoid arthritis, osteoarthritis, pneumocystis carinii, acutepancreatitis, inflammatory airway disease and bone and joint disorders.

The prominent expression of cathepsin K in osteoclasts andosteoclast-related multinucleated cells and its high collagenolyticactivity suggest that the enzyme is involved in ososteoclast-mediatedbone resorption and, hence, in bone abnormalities such as occurs inosteoporosis. In addition, cathepsin K expression in the lung and itselastinolytic activity suggest that the enzyme plays a role in pulmonarydisorders as well.

Cathepsin L is implicated in normal lysosomal proteolysis as well asseveral disease states, including, but not limited to, metastasis ofmelanomas.

Cathepsin S is implicated in Alzheimer's disease and certain autoimmunedisorders, including, but not limited to juvenile onset diabetes,multiple sclerosis, pemphigus vulgaris, Graves' disease, myastheniagravis, systemic lupus erythemotasus, rheumatoid arthritis, neuropathicpain, and Hashimoto's thyroiditis. In addition, cathepsin S isimplicated in: allergic disorders, including, but not limited to asthma;and allogeneic immune responses, including, but not limited to,rejection of organ transplants or tissue grafts.

In view of the number of diseases wherein it is recognized that anincrease in cysteine protease activity contributes to the pathologyand/or symptomatology of the disease, molecules which inhibit theactivity of this class of enzymes, in particular molecules whichinhibitor cathepsins B, K, L, F, and/or S, will therefore be useful astherapeutic agents.

BRIEF SUMMARY OF THE INVENTION

In one aspect, this invention is directed to a compound of Formula (I):

wherein:

R¹ is hydrogen, alkyl, haloalkyl, or alkoxyalkyl;

R² is hydrogen, alkyl, haloalkyl, carboxyalkyl, alkoxycarbonylalkyl,cycloalkyl, cycloalkylalkyl, aryl, aralkyl, heteroaryl, heteroaralkyl,heterocyclyl, heterocyclylalkyl, cyano, or -alkylene-X—R⁹ (where X is—O—, —NR¹⁰—, —CONR¹¹—, —S(O)_(n1)—, —NR¹²CO—, —CO—, or —C(O)O—, where n1is 0-2 and R⁹, R¹⁰, R¹¹, and R¹² are independently hydrogen, alkyl,haloalkyl, cycloalkyl, cycloalkylalkyl, aryl, aralkyl, heteroaryl, orheteroaralkyl); wherein the aromatic or alicyclic ring in R² isoptionally substituted with one, two, or three R^(a) independentlyselected from alkyl, haloalkyl, alkoxy, hydroxy, haloalkoxy, halo,carboxy, alkoxycarbonyl, amino, monsubstituted amino, disubstitutedamino, nitro, aryloxy, benzyloxy, acyl, or arylsulfonyl, and furtherwherein the aromatic or alicyclic ring in R^(a) is optionallysubstituted with one or two substituents independently selected fromalkyl, halo, alkoxy, haloalkyl, haloalkoxy, hydroxy, amino, alkylamino,dialkylamino, carboxy, or alkoxycarbonyl; or

R¹ and R² taken together with the carbon atom to which both R¹ and R²are attached form

-   -   (i) cycloalkylene optionally substituted with one or two R^(b)        independently selected from alkyl, halo, alkylamino,        dialkylamino, aryl, aralkyl, cycloalkyl, cycloalkylalkyl,        heteroaryl, heteroaralkyl, alkoxycarbonyl, or aryloxycarbonyl;    -   (ii) a four-atom heterocyclylalkylene ring; or    -   (iii) heterocyclylalkylene optionally substituted with one to        four R^(c) independently selected from alkyl, haloalkyl,        hydroxy, hydroxyalkyl, alkoxyalkyl, alkoxyalkyloxyalkyl,        aryboxyalkyl, heteroaryloxyalkyl, aminoalkyl, acyl, aryl,        aralkyl, heteroaryl, heteroaralkyl, heterocyclyl,        heterocyclylalkyl, cycloalkyl, cycloalkylalkyl, —S(O)_(n2)R¹⁴,        -alkylene-S(O)_(n2)—R¹⁵, —COOR¹⁶, -alkylene-COOR¹⁷, —CONR¹⁸R¹⁹,        or -alkylene-CONR²⁰R²¹ (where n2 is 0-2 and R¹⁴-R¹⁸ and R²⁰ are        independently hydrogen, alkyl, haloalkyl, aryl, aralkyl,        heteroaryl, heteroaralkyl, cycloalkyl, cycloalkylalkyl, or        heterocyclyl and R¹⁹ and R²¹ are independently hydrogen or        alkyl);        wherein the aromatic or alicyclic ring in the groups attached to        cycloalkylene or heterocyclylalkylene is optionally substituted        with one, two, or three substituents independently selected from        alkyl, haloalkyl, cycloalkyl, cycloalkylalkyl, aralkyl,        aryloxycarbonyl, alkoxy, hydroxy, haloalkoxy, halo, carboxy,        alkoxycarbonyl, amino, monsubstituted amino, disubstituted        amino, or acyl;

R³ is hydrogen or alkyl;

R⁵ is hydrogen or alkyl;

R⁶ is hydrogen, alkyl, haloalkyl, cycloalkyl, aryl, aralkyl, heteroaryl,heteroaralkyl, heterocyclyl, or -alkylene-X²—R²⁵ (where X² is —NR²⁶—,—O—, —S(O)_(n4)—, —CO—, —COO—, —COO—, —NR²⁶CO—, —CONR²⁶—, —NR²⁶SO₂—,—SO₂NR²⁶—, —NR²⁶COO—, —OCONR²⁶—NR²⁶CONR²⁷—, or —NR²⁶SO₂NR²⁷—, where R²⁶and R²⁷ are independently hydrogen, alkyl, or acyl, n4 is 0-2, and R²⁵is hydrogen, alkyl, haloalkyl, cycloalkyl, cycloalkylalkyl,heterocyclyl, heterocyclylalkyl, aryl, aralkyl, heteroaryl, orheteroaralkyl), wherein said alkylene chain in R⁶ is optionallysubstituted with one to six halo and the aromatic or alicyclic rings inR⁶ are optionally substituted by one, two, or three R^(e) independentlyselected from alkyl, halo, hydroxy, hydroxyalkyl, hydroxyalkoxy, alkoxy,alkoxyalkyl, alkoxyalkyloxy, haloalkyl, haloalkoxy, oxo, cyano, nitro,acyl, aryl, aralkyl, aryloxy, aralkyloxy, arylsulfonyl, heteroaryl,heteroaralkyl, heteroaryloxy, heteroaralkyloxy, heteroarylsulfonyl,heterocyclyl, heterocyclylalkyl, cycloalkyl, cycloalkylalkyl, carboxy,alkoxycarbonyl, alkylsulfonyl, aminosulfonyl, or aminoalkyl, and furtherwhere the aromatic or alicyclic ring in R^(e) is optionally substitutedwith one, two or three R^(f) independently selected from alkyl, alkoxy,haloalkyl, haloalkoxy, halo, hydroxy, carboxy, cyano, nitro, aryl orcycloalkyl;

R⁷ is haloalkyl or haloalkoxy, either of which is optionally substitutedwith alkoxy or alkoxyalkyloxy;

R⁸ is hydrogen, alkyl, alkoxyalkyl or haloalkyl; or

R⁶ and R⁸ together with the carbon atom to which they are attached formcycloalkylene or heterocyclylalkylene wherein said cycloalkylene isoptionally substituted with one to four substituents independentlyselected from alkyl, halo, haloalkyl, hydroxy, or alkoxy andheterocyclylalkylene is optionally substituted with one or twosubstituents independently selected from alkyl, halo, haloalkyl,cycloalkyl, hydroxy, or alkoxy;

R²² is hydrogen, fluoro, alkyl, haloalkyl, cycloalkyl, cycloalkylalkyl,heterocyclyl, aryl, aralkyl, heteroaryl, heteroaralkyl, heterocyclyl, orheterocyclylalkyl, wherein the aromatic or alicyclic ring in R²² isoptionally substituted with one, two, or three R^(d) independentlyselected from alkyl, haloalkyl, alkoxy, hydroxy, haloalkoxy, halo,nitro, cyano, carboxy, alkoxycarbonyl, aryl, heteroaryl, cycloalkyl,cycloalkylalkyl, aralkyl, heteroaralkyl, amino, monsubstituted amino,disubstituted amino, or acyl;

Y is -alkylene- or -alkylene-O—, wherein the alkylene group isoptionally substituted with one to six fluoro atoms; and

Z is a direct bond, —O—, -alkylene- or —O-alkylene, wherein the alkyleneportion is optionally substituted with one to six fluoro atoms;

or, a pharmaceutically acceptable salt thereof.

In a second aspect, this invention is directed to a pharmaceuticalcomposition comprising a compound of Formula (I), individualstereoisomers or a mixture thereof; or a pharmaceutically acceptablesalt thereof in admixture with one or more suitable excipients.

In a third aspect, this invention is directed to a method for treating adisease in an animal mediated by cysteine proteases, the cysteineprotease being cathepsin S in one embodiment, which method comprisesadministering to the animal a pharmaceutical composition comprising atherapeutically effective amount of a compound of Formula (I), anindividual stereoisomer or a mixture thereof or a pharmaceuticallyacceptable salt thereof in admixture with one or more suitableexcipients.

In a fourth aspect, this invention is directed to processes forpreparing compounds of Formula (I) and the pharmaceutically acceptablesalts thereof.

In a fifth aspect, this invention is directed to a method of treating apatient undergoing a therapy wherein the therapy causes an immuneresponse, in one embodiment a deleterious immune response, in thepatient comprising administering to the patient a compound of Formula(I), an individual stereoisomer or a mixture thereof; or apharmaceutically acceptable salt thereof. In one embodiment, the immuneresponse is mediated by MHC class II molecules. The compound of thisinvention can be administered prior to, simultaneously, or after thetherapy. In one embodiment, the therapy involves treatment with abiologic. In another embodiment, the therapy involves treatment with asmall molecule.

The biologic can be a protein or an antibody. In one embodiment, thebiologic is a monoclonal antibody. The biologic can be, but is notlimited to, Remicade®, Refacto®, Referon-A®, Factor VIII, Factor VII,Betaserono®, Epogeno®, Enbrel®, Interferon beta, Botox®, Fabrazyme®,Elspar®, Cerezyme®, Myobloc®, Aldurazyme®, Verluma®, Interferon alpha,Humira®, Aranesp®, Zevalin® or OKT3. In one embodiment, the treatmentinvolves use of heparin, low molecular weight heparin, procainamide orhydralazine.

In a sixth aspect, this invention is directed to a method of treatingimmune response in an animal that is caused by administration of abiologic to the animal, which method comprises administering to theanimal in need of such treatment a therapeutically effective amount of acompound of Formula (I), an individual stereoisomer or a mixturethereof, or a pharmaceutically acceptable salt thereof.

In a seventh aspect, this invention is directed to a method ofconducting a clinical trial for a biologic comprising administering toan individual participating in the clinical trial a compound of Formula(I), an individual stereoisomer or a mixture thereof or apharmaceutically acceptable salt thereof with the biologic.

In an eighth aspect, this invention is directed to a method ofprophylactically treating a person undergoing treatment with a biologicwith a compound of Formula (I), an individual stereoisomer or a mixturethereof or a pharmaceutically acceptable salt thereof to treat theimmune response caused by the biologic in the person.

In a ninth aspect, this invention is directed to a method of determiningthe loss in the efficacy of a biologic in an animal due to the immuneresponse caused by the biologic, the method comprising administering thebiologic to the animal in the presence and absence of a compound ofFormula (I); an individual stereoisomer or a mixture thereof or apharmaceutically acceptable salt thereof.

In a tenth aspect, this invention is directed to a method of improvingefficacy of a biologic in an animal comprising administering thebiologic to the animal with a compound of Formula (I), an individualstereoisomer or a mixture thereof or a pharmaceutically acceptable saltthereof.

In an eleventh aspect, this invention is directed to the use of acompound of Formula (I), an individual stereoisomer or a mixture thereofor a pharmaceutically acceptable salt thereof for the manufacture of amedicament. In one embodiment, the medicament is for use in thetreatment of a disease mediated by cysteine proteases, such as forexample Cathepsin S.

In a twelfth aspect, this invention is directed to the use of a compoundof Formula (I), an individual stereoisomer or a mixture thereof or apharmaceutically acceptable salt thereof for the manufacture of amedicament for combination therapy with a biologic, wherein the compoundof this invention treats the immune response caused by the biologic. Inone embodiment, the compound(s) of the invention is administered priorto the administration of the biological agent. In another embodiment,the compound(s) of the invention is administered concomitantly with thebiological agent. In a further embodiment, the compound(s) of theinvention is administered after the administration of the biologicalagent.

BRIEF DESCRIPTION OF THE DRAWINGS

Not applicable

DETAILED DESCRIPTION OF THE INVENTION

Throughout this specification and the claims that follow, unless thecontext requires otherwise, the word “comprise” and variations such as“comprises” and “comprising” will be understood to imply the inclusionof a stated integer or step or group of integers or steps but not theexclusion of any other integer or step or group of integers or steps.

As used herein the singular forms “a”, “and”, and “the” include pluralreferents unless the context clearly dictates otherwise. For example, “acompound” refers to one or more of such compounds, while “the enzyme”includes a particular enzyme as well as other family members andequivalents thereof as known to those skilled in the art.

Furthermore, as used in the specification and appended claims, unlessspecified to the contrary, the following terms have the meaningindicated:

“Alicyclic” means a moiety characterized by arrangement of the carbonatoms in closed non-aromatic ring structures e.g., cycloalkyl andheterocyclyl rings as defined herein.

“Alkyl” represented by itself means a straight or branched, saturatedaliphatic radical containing one to six carbon atoms, unless otherwiseindicated e.g., alkyl includes methyl, ethyl, propyl, isopropyl, butyl,sec-butyl, isobutyl, tert-butyl, and the like.

“Alkylene”, unless indicated otherwise, means a straight or branched,saturated aliphatic, divalent radical having the number of one to sixcarbon atoms, e.g., methylene (—CH₂—), ethylene (—CH₂CH₂—), trimethylene(—CH₂CH₂CH₂—), tetramethylene (—CH₂CH₂CH₂CH₂—) 2-methyltetramethylene(—CH₂CH(CH₃)CH₂CH₂—), pentamethylene (—CH₂CH₂CH₂CH₂CH₂—), and the like.

“Amino” means the —NH₂ radical. Unless indicated otherwise, thecompounds of the invention containing amino moieties include protectedderivatives thereof. Suitable protecting groups for amino moietiesinclude acetyl, tert-butoxycarbonyl, benzyloxycarbonyl, and the like.

“Alkylamino” or “dialkylamino” refers to a —NHR or a —NRR′ radical,respectively, where R and R′ are independently an alkyl group as definedabove, e.g., methylamino, dimethylamino, and the like.

“Alkoxy” refers to a —OR radical where R is an alkyl group as definedabove, e.g., methoxy, ethoxy, and the like.

“Alkoxycarbonyl” refers to a —C(O)OR radical where R is an alkyl groupas defined above, e.g., methoxycarbonyl, ethoxycarbonyl, and the like.

“Alkoxycarbonylalkyl” means an -(alkylene)-C(O)OR radical where R isalkyl as defined above, e.g., methoxycarbonylmethyl, 2-, or3-ethoxycarbonylmethyl, and the like.

“Alkoxyalkyl” means a linear monovalent hydrocarbon radical of one tosix carbon atoms or a branched monovalent hydrocarbon radical of threeto six carbons substituted with at least one alkoxy group, preferablyone or two alkoxy groups, as defined above, e.g., 2-methoxyethyl, 1-,2-, or 3-methoxypropyl, 2-ethoxyethyl, and the like.

“Alkoxyalkyloxy” refers to a —OR radical where R is alkoxyalkyl asdefined above, e.g., methoxymethyloxy, methoxyethyloxy, and the like.

“Alkoxyalkyloxyalkyl” refers to an -(alkylene)-O-(alkylene)-OR radicalwhere R is an alkyl group as defined above, e.g.,2-methoxyethyloxymethyl, 3-methoxypropyloxyethyl, and the like.

“Aminoalkyl” means a linear monovalent hydrocarbon radical of one to sixcarbon atoms or a branched monovalent hydrocarbon radical of three tosix carbons substituted with at least one, preferably one or two, —NRR′where R is hydrogen, alkyl, or —COR^(a) where R^(a) is alkyl, and R′ ishydrogen or alkyl as defined above, e.g., aminomethyl, methylaminoethyl,dimethylaminoethyl, 1,3-diaminopropyl, acetylaminopropyl, and the likee.g., aminosulfonyl, methylaminosulfonyl, dimethylaminosulfonyl, and thelike.

“Aminosulfonyl” refers to a —SO₂R radical where R is —NRR′ where R ishydrogen, alkyl, or —COR^(a) where R^(a) is alkyl, and R′ is hydrogen oralkyl as defined above, e.g., aminosulfonyl, methylaminosulfonyl,dimethylaminosulfonyl, and the like.

“Alkylsulfonyl” refers to a —SO₂R radical where R is an alkyl group asdefined above, e.g., methylsulfonyl, ethylsulfonyl, and the like.

“Acyl” refers to a —COR radical where R is hydrogen, alkyl, haloalkyl,aryl, aralkyl, heteroaryl, heteroaralkyl, or heterocyclyl as definedherein, e.g., formyl, acetyl, trifluoroacetyl, benzoyl,piperazin-1-ylcarbonyl, and the like.

“Animal” includes humans, non-human mammals (e.g., dogs, cats, rabbits,cattle, horses, sheep, goats, swine, deer, and the like) and non-mammals(e.g., birds, and the like).

“Aromatic” refers to a moiety wherein the constituent atoms make up anunsaturated ring system, all atoms in the ring system are sp² hybridizedand the total number of pi electrons is equal to 4n+2,

“Aryl” refers to a monocyclic or fused bicyclic ring assembly containing6 to 10 ring carbon atoms wherein each ring is aromatic, e.g., phenyl,naphthyl, and the like.

“Aralkyl” refers to an -(alkylene)-R radical where R is aryl as definedabove, e.g., benzyl, phenethyl, and the like.

“Aryloxy” refers to a —OR radical where R is aryl as defined above,e.g., phenoxy and the like.

“Aralkyloxy” refers to a —OR radical where R is aralkyl as definedabove, e.g., benzyloxy and the like.

“Aryloxyalkyl” refers to an -(alkylene)-OR radical where R is aryl asdefined above, e.g., phenoxymethyl, 2- or 3-phenoxymethyl, and the like

“Aryloxycarbonyl” refers to a —C(O)OR radical where R is aryl as definedabove, e.g., phenyloxycarbonyl and the like.

“Arylsulfonyl” refers to a —SO₂R radical where R is an aryl group asdefined above, e.g., phenylsulfonyl and the like.

“Biologic” means a therapeutic agent originally derived from livingorganisms for the treatment or management of a disease. Examplesinclude, but are not limited to, proteins (recombinant and plasmaderived), monoclonal or polyclonal antibodies, humanized or murineantibodies, toxins, hormones, and the like. Biologics are currentlyavailable for the treatment of a variety of diseases such as cancer,rheumatoid arthritis, and haemophilia.

“Carboxy” refers to the —C(O)OH radical.

“Carboxyalkyl” refers to an -(alkylene)-C(O)OH radical, e.g.,carboxymethyl, carboxyethyl, and the like.

“Cycloalkyl” refers to a monovalent saturated or partially unsaturated,monocyclic ring containing three to eight ring carbon atoms, e.g.,cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclohexenyl,2,5-cyclohexadienyl, and the like.

“Cycloalkylalkyl” refers to an -(alkylene)-R radical where R iscycloalkyl as defined above, e.g., cyclopropylmethyl, cyclobutylethyl,cyclobutylmethyl, and the like

“Cycloalkylene” refers to a divalent saturated or partially unsaturatedmonocyclic ring containing three to eight ring carbon atoms. Forexample, the instance wherein “R¹ and R² together with the carbon atomto which both R¹ and R² are attached form cycloalkylene” includes, butis not limited to, the following:

and the like.

“1-Alkylcyclopentylmethyl or -ethyl and 1-Alkylcyclohexylmethyl or-ethyl” means a radical having the formula:

respectively; e.g., 1-methylcyclopentylmethyl, 1-methylcyclohexylmethyl,and the like

“Disubstituted amino” refers to a —NRR′ radical where R is alkyl, aryl,aralkyl, heteroaryl, heteroaralkyl, or heterocyclyl and R′ is alkyl,aryl, aralkyl, heteroaryl, heteroaralkyl, cycloalkyl, heterocyclyl,cycloalkylalkyl, hydroxyalkyl, alkoxyalkyl, or acyl as defined herein.Representative examples include, but are not limited to, dimethylamino,methylphenylamino, benzylmethylamino, acetylmethylamino, and the like.

“Disease” specifically includes any unhealthy condition of an animal orpart thereof and includes an unhealthy condition that may be caused by,or is incident to, medical or veterinary therapy applied to that animal,i.e., the “side effects” of such therapy.

“Deleterious immune response” means an immune response that preventseffective treatment of a patient or causes disease in a patient. As anexample, dosing a patient with a murine antibody either as a therapy oras a diagnostic agent causes the production of human antimouseantibodies that prevent or interfere with subsequent treatments. Theincidence of antibody formation versus pure murine monoclonals canexceed 70%. (see Khazaeli, M. B. et al. J. Immunother. 1994, 15, pp42-52; Dillman R. O. et al. Cancer Biother. 1994, 9, pp 17-28; andReinsberg, J. Hybridoma. 1995, 14, pp 205-208). Additional examples ofknown agents that suffer from deleterious immune responses areblood-clotting factors such as factor VIII. When administered tohemophilia A patients, factor VIII restores the ability of the blood toclot. Although factor VIII is a human protein, it still elicits animmune response in hemophiliacs as endogenous factor VIII is not presentin their blood and thus it appears as a foreign antigen to the immunesystem. Approximately 29-33% of new patients will produce antibodiesthat bind and neutralize the therapeutically administered factor VIII(see Lusher J. M. Semin Thromb Hemost. 2002, 28(3), pp 273-276). Theseneutralizing antibodies require the administration of larger amounts offactor VIII in order to maintain normal blood clotting parameters; anexpensive regimen of treatment in order to induce immune tolerance (seeBriet E et al. Adv. Exp. Med. Bio. 2001, 489, pp 89-97). Anotherimmunogenic example is adenoviral vectors. Retroviral therapy remainsexperimental and is of limited utility. One reason is that theapplication of a therapeutic virus generates an immune response capableof blocking any subsequent administration of the same or similar virus(see Yiping Yang et al. J. of Virology. 1995, 69, pp 2004-2015). Thisensures that retroviral therapies must be based on the transientexpression of a protein or the direct incorporation of viral sequenceinto the host genome. Directed research has identified multiple viralneutralizing epitopes recognized by host antibodies (see Hanne,Gahery-Segard et al. J. of Virology 1998. 72, pp 2388-2397) suggestingthat viral modifications will not be sufficient to overcome thisobstacle. This invention will enable a process whereby an adenoviraltherapy will have utility for repeated application. Another example ofan immunogenic agent that elicits neutralizing antibodies is thewell-known cosmetic agent Botox. Botulin toxin protein, is purified fromthe fermentation of Clostridium botulinum. As a therapeutic agent, it isused for muscle disorders such as cervical dystonia in addition tocosmetic application. After repeated exposure patients generateneutralizing antibodies to the toxin, which results in reduced efficacy(see Birklein F. et al. Ann Neurol. 2002, 52, pp 68-73 and Rollnik, J.D. et al. Neurol. Clin. Neurophysiol. 2001, 2001(3), pp 2-4).

A “deleterious immune response” also encompasses diseases caused bytherapeutic agents. A specific example of this is the immune response totherapy with recombinant human erythropoietin (EPO). Erythropoietin isused to stimulate the growth or red cells and restore red blood cellcounts in patients who have undergone chemotherapy or dialysis. A smallpercentage of patients develop antibodies to EPO and subsequently areunresponsive to both therapeutically administered EPO and their ownendogenous EPO (see Casadevall, N. et al., NEJM. 2002, 346, pp 469-475).They contract a disorder, pure red cell aplasia, in which red blood cellproduction is severely diminished (see Gershon S. K. et. al. NEJM. 2002,346, pp 1584-1586). This complication of EPO therapy is lethal ifuntreated. Another specific example is the murine antibody OKT3 (a.k.a.,Orthoclone), a monoclonal antibody directed towards CD-3 domain ofactivated T-cells. In clinical trials 20-40% of patients administeredOKT3 produce antibodies versus the therapy. These antibodies, besidesneutralizing the therapy, also stimulate a strong host immune reaction.The immune reaction is severe enough that patients with high titers ofhuman anti-mouse antibodies are specifically restricted from taking thedrug (see Orthoclone package label). Another example is a human antibodytherapeutic. Humira® is a monoclonal antibody directed against TNF andis used to treat rheumatoid arthritis patients. When taken alone ˜12% ofpatients develop neutralizing antibodies. In addition, a smallpercentage of patients given the drug also contract a systemic lupuserthematosus-like condition that is an IgG-mediated immune responseinduced by the therapeutic agent (see Humira package label). Anotherexample of “deleterious immune response” is a host reaction to smallmolecule drugs. It is known to those skilled in the art that certainchemical structures will conjugate with host proteins to stimulateimmune recognition (see Ju. C. et al. 2002, Current Drug Metabolism 3,pp 367-377 and Kimber I. et al. 2002, Toxicologic Pathology 30, pp54-58.) A substantial portion of this host reactions are IgG mediated.Specific “deleterious immune responses” that are IgG mediated include,but are not limited to, hemolytic anemia, Steven-Johnson syndrome anddrug-induced Lupus,

“Four-atom heterocyclylalkylene” refers to a saturated divalentmonocyclic radical of 4 carbon ring atoms wherein one of the ring carbonatoms is replaced by a heteroatom selected from —NR— where R ishydrogen, alkyl, acyl, alkylsulfonyl, aminosulfonyl, hydroxyalkyl,alkoxyalkyl, —O—, —S—, —SO—, or —S(O)₂—. Representative examplesinclude, but are not limited to, rings such as:

and the like.

“Halo” refers to fluoro, chloro, bromo or iodo.

“Haloalkyl” refers to alkyl as defined above substituted by one or more,preferably one to five, “halo” atoms, as such terms are defined in thisApplication. Haloalkyl includes monohaloalkyl, dihaloalkyl,trihaloalkyl, perhaloalkyl and the like, e.g. chloromethyl,dichloromethyl, difluoromethyl, trifluoromethyl, 2,2,2-trifluoroethyl,perfluoroethyl, 2,2,2-trifluoro-1,1-dichloroethyl, and the like.

“Haloalkoxy” refers to a —OR radical where R is haloalkyl group asdefined above, e.g., trifluoromethoxy, 2,2,2-trifluoroethoxy,difluoromethoxy, and the like.

“Heteroaryl” as a group or part of a group denotes an aromaticmonocyclic or multicyclic moiety of 5 to 10 ring atoms in which one ormore, preferably one, two, or three, of the ring atom(s) is(are)selected from nitrogen, oxygen or sulfur, the remaining ring atoms beingcarbon. Representative heteroaryl rings include, but are not limited to,pyrrolyl, furanyl, thienyl, oxazolyl, isoxazolyl, thiazolyl, imidazolyl,triazolyl, tetrazolyl, pyridinyl, pyrimidinyl, pyrazinyl, pyridazinyl,indolyl, benzofuranyl, benzothienyl, benzimidazolyl, quinolinyl,isoquinolinyl, quinazolinyl, quinoxalinyl, pyrazolyl, and the like.

“Heteroaralkyl” refers to an -(alkylene)-R radical where R is heteroarylas defined above, e.g., pyridinylmethyl, 1- or 2-furanylethyl,imidazolylmethyl, and the like,

“Heteroaryloxyalkyl” refers to a -(alkylene)-OR radical where R isheteroaryl as defined above, e.g., furanyloxymethyl, 2- or3-indolyloxyethyl, and the like.

“Heteroaryloxy” refers to a —OR radical where R is heteroaryl as definedabove.

“Heteroaralkyloxy” refers to a —OR radical where R is heteroaralkyl asdefined above.

“Heteroarylsulfonyl” refers to a —SO₂R radical where R is an heteroarylgroup as defined above, e.g., pyridinylsulfonyl, and the like.

“Heterocyclyl” refers to a saturated or partially unsaturated, mono orbicyclic radical of 5 or 6 carbon ring atoms wherein one or more,preferably one, two, or three of the ring carbon atoms are replaced by aheteroatom selected from —N═, —N—, —O—, —S—, —SO—, or —S(O)₂— andfurther wherein one or two ring atoms are optionally replaced by a keto(—CO—) group. The heterocyclyl ring is optionally fused to cycloalkyl,aryl or heteroaryl ring as defined herein. Representative examplesinclude, but are not limited to, imidazolidinyl, morpholinyl,thiomorpholinyl, thiomorpholino-1-oxide, thiomorpholino-1,1-dioxide,tetrahydropyranyl, tetrahydrothiopyranyl, 1-oxo-tetrahydrothiopyranyl,1,1-dioxotetrathiopyranyl, indolinyl, piperazinyl, piperidyl,pyrrolidinyl, pyrrolinyl, quinuclidinyl, and the like.

“Heterocyclylalkyl” refers to an -(alkylene)-heterocyclyl radical asdefined herein. Representative examples include, but are not limited to,imidazolidin-1-ylmethyl, morpholin-4-ylmethyl, thiomorpholin-4-ylmethyl,thiomorpholin-4-ylmethyl-1-oxide, indolinylethyl, piperazinylmethyl orethyl, piperidylmethyl or ethyl, pyrrolidinylmethyl or ethyl, and thelike.

“Heterocyclylalkylene” refers to a divalent heterocyclyl group, asdefined herein, e.g., the instance wherein “R¹ and R² together with thecarbon atom to which both R¹ and R² are attached formheterocyclylalkylene” includes, but is not limited to, the following:

in which R is a substituent of a heterocyclyl group as disclosed herein.

“Hydroxy” means the —OH radical. Unless indicated otherwise, thecompounds of the invention containing hydroxy radicals include protectedderivatives thereof. Suitable protecting groups for hydroxy moietiesinclude benzyl and the like.

“Hydroxyalkyl” means a linear monovalent hydrocarbon radical of one tosix carbon atoms or a branched monovalent hydrocarbon radical of threeto six carbons substituted with one or two hydroxy groups, provided thatif two hydroxy groups are present they are not both on the same carbonatom. Representative examples include, but are not limited to,hydroxymethyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl,1-(hydroxymethyl)-2-methylpropyl, 2-hydroxybutyl, 3-hydroxybutyl,4-hydroxybutyl, 2,3-dihydroxypropyl, 1-(hydroxymethyl)-2-hydroxyethyl,2,3-dihydroxybutyl, 3,4-dihydroxybutyl and2-(hydroxymethyl)-3-hydroxypropyl, preferably 2-hydroxyethyl,2,3-dihydroxypropyl, and 1-(hydroxymethyl)-2-hydroxyethyl.

“Hydroxyalkyloxy” or “hydroxyalkoxy” refers to a —OR radical where R ishydroxyalkyl as defined above, e.g., hydroxymethoxy, hydroxyethoxy, andthe like.

“Isomers” mean compounds of Formula (I) having identical molecularformulae but differing in the nature or sequence of bonding of theiratoms or in the arrangement of their atoms in space. Isomers that differin the arrangement of their atoms in space are termed “stereoisomers”.Stereoisomers that are not mirror images of one another are termed“diastereomers” and stereoisomers that are nonsuperimposable mirrorimages are termed “enantiomers” or sometimes “optical isomers”. A carbonatom bonded to four nonidentical substituents is termed a “chiralcenter”. A compound with one chiral center has two enantiomeric forms ofopposite chirality is termed a “racemic mixture”. A compound that hasmore than one chiral center has 2^(n-1) enantiomeric pairs, where n isthe number of chiral centers. Compounds with more than one chiral centermay exist as either an individual diastereomer or as a mixture ofdiastereomers, termed a “diastereomeric mixture”. When one chiral centeris present, a stereoisomer may be characterized by the absoluteconfiguration of that chiral center. Absolute configuration refers tothe arrangement in space of the substituents attached to the chiralcenter. Enantiomers are characterized by the absolute configuration oftheir chiral centers and described by the R- and S-sequencing rules ofCahn, Ingold and Prelog. Conventions for stereochemical nomenclature,methods for the determination of stereochemistry and the separation ofstereoisomers are well known in the art (e.g., see “Advanced OrganicChemistry”, 4th edition, March, Jerry, John Wiley & Sons, New York,1992). It is understood that the names and illustration used in thisApplication to describe compounds of Formula (I) are meant to beencompassed all possible stereoisomers.

“Keto” or “oxo” means the (═O) radical.

“Monosubstituted amino” refers to a —NIH radical where R is alkyl, aryl,aralkyl, heteroaryl, heteroaralkyl, cycloalkyl, cycloalkylalkyl,hydroxyalkyl, alkoxyalkyl, or acyl as defined herein. Representativeexamples include, but are not limited to, methylamino, phenylamino,benzylamino, cycloalkylmethylamino, acetylamino, trifluoroacetyl, andthe like.

“Nitro” means the —NO₂ radical.

“Optional” or “optionally” or “may be” means that the subsequentlydescribed event or circumstance may or may not occur, and that thedescription includes instances where the event or circumstance occursand instances in which it does not. For example, the phrase “wherein thearomatic ring in R^(a) is optionally substituted with one or twosubstituents independently selected from alkyl” means that the aromaticring may or may not be substituted with alkyl in order to fall withinthe scope of the invention.

The present invention also includes N-oxide derivatives of a compound ofFormula (I). “N-oxide derivative” mean a compound of Formula (I) inwhich a nitrogen atom is in an oxidized state (i.e., N→O), e.g.,pyridine N-oxide, and which possesses the desired pharmacologicalactivity.

“Pathology” of a disease means the essential nature, causes anddevelopment of the disease as well as the structural and functionalchanges that result from the disease processes.

“Pharmaceutically acceptable” means that which is useful in preparing apharmaceutical composition that is generally safe, non-toxic and neitherbiologically nor otherwise undesirable and includes that which isacceptable for veterinary use as well as human pharmaceutical use.

“Pharmaceutically acceptable salts” means salts of compounds of Formula(I) which are pharmaceutically acceptable, as defined above, and whichpossess the desired pharmacological activity. Such salts include acidaddition salts formed with inorganic acids such as hydrochloric acid,hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and thelike; or with organic acids such as acetic acid, propionic acid,hexanoic acid, heptanoic acid, cyclopentanepropionic acid, glycolicacid, pyruvic acid, lactic acid, malonic acid, succinic acid, malicacid, maleic acid, fumaric acid, tartaric acid, citric acid, benzoicacid, o-(4-hydroxybenzoyl)benzoic acid, cinnamic acid, mandelic acid,methylsulfonic acid, ethanesulfonic acid, 1,2-ethanedisulfonic acid,2-hydroxy-ethanesulfonic acid, benzenesulfonic acid,p-chlorobenzenesulfonic acid, 2-naphthalenesulfonic acid,p-toluenesulfonic acid, camphorsulfonic acid,4-methylbicyclo[2.2.2]oct-2-ene-1-carboxylic acid, glucoheptonic acid,3-phenylpropionic acid, trimethylacetic acid, tertiary butylacetic acid,lauryl sulfuric acid, gluconic acid, glutamic acid, hydroxynaphthoicacid, salicylic acid, stearic acid, muconic acid and the like.

Pharmaceutically acceptable salts also include base addition salts whichmay be formed when acidic protons present are capable of reacting withinorganic or organic bases. Acceptable inorganic bases include sodiumhydroxide, sodium carbonate, potassium hydroxide, aluminum hydroxide andcalcium hydroxide. Acceptable organic bases include ethanolamine,diethanolamine, triethanolamine, tromethamine, N-methylglucamine and thelike.

The present invention also includes prodrugs of a compound of Formula(I). “Prodrug” means a compound that is convertible in vivo by metabolicmeans (e.g. by hydrolysis) to a compound of Formula (I). For example, anester of a compound of Formula (I) containing a hydroxy group may beconvertible by hydrolysis in vivo to the parent molecule. Alternativelyan ester of a compound of Formula (I) containing a carboxy group may beconvertible by hydrolysis in vivo to the parent molecule. Suitableesters of compounds of Formula (I) containing a hydroxy group, are forexample acetates, citrates, lactates, tartrates, malonates, oxalates,salicylates, propionates, succinates, fumarates, maleates,methylene-bis-b-hydroxynaphthoates, gentisates, isethionates,di-p-toluoyltartrates, methylsulphonates, ethanesulphonates,benzenesulphonates, p-toluenesulphonates, cyclohexylsulphamates andquinates. Suitable esters of compounds of Formula (I) containing acarboxy group are for example those described by Leinweber, F. J. DrugMetab. Res., 1987, 18, page 379. An especially useful class of esters ofcompounds of Formula (I) containing a hydroxy group may be formed fromacid moieties selected from those described by Bundgaard et al., J. Med.Chem., 1989, 32, pp 2503-2507, and include substituted(aminomethyl)-benzoates, for example, dialkylamino-methylbenzoates inwhich the two alkyl groups may be joined together and/or interrupted byan oxygen atom or by an optionally substituted nitrogen atom, e.g. analkylated nitrogen atom, more especially (morpholinomethyl)benzoates,e.g. 3- or 4-(morpholinomethyl)-benzoates, and(4-alkylpiperazin-1-yl)benzoates, e.g.3-OR⁴-(4-alkylpiperazin-1-yl)benzoates.

“Protected derivatives” means derivatives of compounds of Formula (I) inwhich a reactive site or sites are blocked with protecting groups.Protected derivatives of compounds of Formula (I) are useful in thepreparation of compounds of Formula (I) or in themselves may be activecysteine protease (such as Cathepsin S) inhibitors. A comprehensive listof suitable protecting groups can be found in T. W. Greene, ProtectiveGroups in Organic Synthesis, 3rd edition, John Wiley & Sons, Inc. 1999.

The expression “ . . . wherein the aromatic or alicyclic ring in R², R⁴,or R⁶ is optionally substituted with one to three R^(a), R^(d), orR^(e), respectively . . . ” refers to all the groups attached to R², R⁴,or R⁶ that contain an aromatic or alicyclic ring being optionallysubstituted with one to three R^(a), R^(d), or R^(e) respectively. Thearomatic or alicyclic ring may be directly attached to R², R⁴, or R⁶ orbe part of a group that is directly attached to R², R⁴, or R⁶.

“Therapeutically effective amount” means that amount that, whenadministered to an animal for treating a disease, is sufficient toeffect such treatment for the disease.

“Treatment” or “treating” means any administration of a compound of thepresent invention and includes:

-   -   (1) preventing the disease from occurring in an animal which may        be predisposed to the disease but does not yet experience or        display the pathology or symptomatology of the disease,    -   (2) inhibiting the disease in an animal that is experiencing or        displaying the pathology or symptomatology of the diseased        (i.e., arresting further development of the pathology and/or        symptomatology), or    -   (3) ameliorating the disease in an animal that is experiencing        or displaying the pathology or symptomatology of the diseased        (i.e., reversing the pathology and/or symptomatology).

“Treatment” or “treating” with respect to combination therapy (i.e., usewith a biologic) means any administration of a compound of the presentinvention and includes:

-   -   (1) preventing the immune response from occurring in an animal        which may be predisposed to the immune response but does not yet        experience or display the pathology or symptomatology of the        immune response;    -   (2) inhibiting the immune response in an animal that is        experiencing or displaying the pathology or symptomatology of        the immune response (i.e., arresting further development of the        pathology and/or symptomatology); or    -   (3) ameliorating the immune response in an animal that is        experiencing or displaying the pathology or symptomatology of        the immune response (i.e., reducing in degree or severity, or        extent or duration, the overt manifestations of the immune        response or reversing the pathology and/or symptomatology, e.g.,        reduced binding and presentation of antigenic peptides by MHC        class II molecules, reduced activation of T-cells and B-cells,        reduced humoral and cell-mediated responses and, as appropriate        to the particular immune response, reduced inflammation,        congestion, pain, necrosis, reduced loss in the efficacy of a        biologic agent, and the like).

EMBODIMENTS OF THE INVENTION

In one particular aspect, the invention is directed to a compound ofFormula (I) wherein:

R¹ is hydrogen or alkyl;

R² is hydrogen, alkyl, haloalkyl, carboxyalkyl, alkoxycarbonylalkyl,cycloalkyl, cycloalkylalkyl, aryl, aralkyl, heteroaryl, heteroaralkyl,heterocyclyl, heterocyclylalkyl, cyano, or -alkylene-X—R⁹ (where X is—O—, —NR¹⁰—, —CONR¹¹—, —S(O)_(n1)—, —NR¹²CO—, —CO—, or —C(O)O— where n1is 0-2, and R⁹, R¹⁰, R¹¹, and R¹² are independently hydrogen, alkyl,haloalkyl, cycloalkyl, cycloalkylalkyl, aryl, aralkyl, heteroaryl, orheteroaralkyl) wherein the aromatic or alicyclic ring in R² isoptionally substituted with one, two, or three R^(a) independentlyselected from alkyl, haloalkyl, alkoxy, hydroxy, haloalkoxy, halo,carboxy, alkoxycarbonyl, amino, monsubstituted amino, disubstitutedamino, nitro, aryloxy, benzyloxy, acyl, or arylsulfonyl and furtherwhere the aromatic or alicyclic ring in R^(a) is optionally substitutedwith one or two substituents independently selected from alkyl, halo,alkoxy, haloalkyl, haloalkoxy, hydroxy, amino, alkylamino, dialkylamino,carboxy, or alkoxycarbonyl; or

R¹ and R² taken together with the carbon atom to which both R¹ and R²are attached form

-   -   (i) cycloalkylene optionally substituted with one or two R^(b)        independently selected from alkyl, halo, alkylamino,        dialkylamino, aryl, aralkyl, cycloalkyl, cycloalkylalkyl,        heteroaryl, heteroaralkyl, alkoxycarbonyl, or aryloxycarbonyl;    -   or    -   (iii) heterocyclylalkylene optionally substituted with one to        four R^(c) which are independently selected from alkyl,        haloalkyl, hydroxy, hydroxyalkyl, alkoxyalkyl,        alkoxyalkyloxyalkyl, aryloxyalkyl, heteroaryloxyalkyl,        aminoalkyl, acyl, aryl, aralkyl, heteroaryl, heteroaralkyl,        heterocyclyl, heterocyclylalkyl, cycloalkyl, cycloalkylalkyl,        —S(O)_(n2)R¹⁴, -alkylene-S(O)_(n2)—R¹⁵, —COOR¹⁶,        -alkylene-COOR¹⁷, —CONR¹⁸R¹⁹, or -alkylene-CONR²⁰R²¹ (where n2        is 0-2 and R¹⁴-R¹⁸ and R²⁰ are independently hydrogen, alkyl,        haloalkyl, aryl, aralkyl, heteroaryl, heteroaralkyl, cycloalkyl,        cycloalkylalkyl, or heterocyclyl and R¹⁹ and R²¹ are        independently hydrogen or alkyl);

wherein the aromatic or alicyclic ring in the groups attached tocycloalkylene or heterocyclylalkylene is optionally substituted withone, two, or three substituents independently selected from alkyl,haloalkyl, alkoxy, hydroxy, haloalkoxy, halo, carboxy, alkoxycarbonyl,amino, monsubstituted amino, disubstituted amino, or acyl;

R³ is hydrogen or alkyl;

R⁵ is hydrogen or alkyl;

R⁶ is hydrogen, alkyl, haloalkyl, cycloalkyl, aryl, aralkyl, heteroaryl,heteroaralkyl, heterocyclyl, or -alkylene-X²—R²⁵ (wherein X² is —NR²⁶—,—O—, —S(O)_(n4)—, —CO—, —COO—, —OCO—, —NR²⁶CO—, —CONR²⁶—, —NR²⁶SO₂—,—SO₂NR²⁶—, —NR²⁶COO—, —OCONR²⁶—, —NR²⁶CONR²⁷—, or —NR²⁶SO₂NR²⁷—, whereR²⁶ and R²⁷ are independently hydrogen, alkyl, or acyl, n4 is 0-2, andR²⁵ is hydrogen, alkyl, haloalkyl, cycloalkyl, cycloalkylalkyl,heterocyclyl, heterocyclylalkyl, aryl, aralkyl, heteroaryl, orheteroaralkyl), wherein said alkylene chain in R⁶ is optionallysubstituted with one to six halo and the aromatic or alicyclic ring inR⁶ is optionally substituted with one, two, or three R^(e) independentlyselected from alkyl, halo, hydroxy, alkoxy, haloalkyl, haloalkoxy, oxo,cyano, nitro, acyl, aryl, aralkyl, heteroaryl, heteroaralkyl,heterocyclyl, cycloalkyl, cycloalkylalkyl, carboxy, or alkoxycarbonyl,and further where the aromatic or alicyclic rings in R^(e) is optionallysubstituted by one, two or three R^(f) independently selected fromalkyl, alkoxy, haloalkyl, haloalkoxy, halo, hydroxy, carboxy, cyano,nitro, aryl or cycloalkyl;

R⁷ is haloalkyl;

R⁸ is hydrogen, alkyl, alkoxyalkyl or haloalkyl; or

R⁶ and R⁸ together with the carbon atom to which they are attached formcycloalkylene or heterocyclylalkylene wherein said cycloalkylene isoptionally substituted with one or two substituents independentlyselected from alkyl, haloalkyl, hydroxy, or alkoxy andheterocyclylalkylene is optionally substituted with one or twosubstituents independently selected from alkyl, haloalkyl, hydroxy, oralkoxy;

R²² is hydrogen, fluoro, alkyl, haloalkyl, cycloalkyl, cycloalkylalkyl,heterocyclyl, aryl, aralkyl, heteroaryl, heteroaralkyl, heterocyclyl, orheterocyclylalkyl, wherein the aromatic or alicyclic ring in R²² isoptionally substituted with one, two, or three R^(d) independentlyselected from alkyl, haloalkyl, alkoxy, hydroxy, haloalkoxy, halo,nitro, cyano, carboxy, alkoxycarbonyl, aryl, heteroaryl, cycloalkyl,cycloalkylalkyl, aralkyl, heteroaralkyl, amino, monsubstituted amino,disubstituted amino, or aryl;

Y is -alkylene- or -alkylene-O—, wherein the alkylene group isoptionally substituted with one to six fluoro atoms; and

Z is a direct bond, —O—, -alkylene- or —O-alkylene, wherein the alkyleneportion is optionally substituted with one to six fluoro atoms;

or, a pharmaceutically acceptable salt thereof.

In another particular aspect, the invention is directed to a compound ofFormula (I) wherein:

R¹ is hydrogen or alkyl;

R² is hydrogen, alkyl, haloalkyl, carboxyalkyl, alkoxycarbonylalkyl,cycloalkyl, cycloalkylalkyl, aryl, aralkyl, heteroaryl, heteroaralkyl,heterocyclyl, heterocyclylalkyl, cyano, -alkylene-X—R⁹ (where X is —O—,—NR¹⁰—, —CONR¹¹—, —S(O)_(n1)—, —NR¹²CO—, —CO—, or —C(O)O— where n1 is0-2, and R⁹, R¹⁰, R¹¹, and R¹² are independently hydrogen, alkyl,haloalkyl, cycloalkyl, cycloalkylalkyl, aryl, aralkyl, heteroaryl, orheteroaralkyl), wherein the aromatic or alicyclic ring in R² isoptionally substituted with one, two, or three R^(a) independentlyselected from alkyl, haloalkyl, alkoxy, hydroxy, haloalkoxy, halo,carboxy, alkoxycarbonyl, amino, monsubstituted amino, disubstitutedamino, nitro, aryloxy, benzyloxy, acyl, or arylsulfonyl and furtherwhere the aromatic or alicyclic ring in R^(a) is optionally substitutedwith one or two substituents independently selected from alkyl, halo,alkoxy, haloalkyl, haloalkoxy, hydroxy, amino, alkylamino, dialkylamino,carboxy, or alkoxycarbonyl; or

R¹ and R² taken together with the carbon atom to which both R¹ and R²are attached form

-   -   (i) cycloalkylene optionally substituted with one or two R^(b)        independently selected from alkyl, halo, alkylamino,        dialkylamino, aryl, aralkyl, cycloalkyl, cycloalkylalkyl,        heteroaryl, heteroaralkyl, alkoxycarbonyl, or aryloxycarbonyl;    -   or,    -   (iii) heterocyclylalkylene optionally substituted with one to        four R^(e) which are independently selected from alkyl,        haloalkyl, hydroxy, hydroxyalkyl, alkoxyalkyl,        alkoxyalkyloxyalkyl, aryloxyalkyl, heteroaryloxyalkyl,        aminoalkyl, acyl, aryl, aralkyl, heteroaryl, heteroaralkyl,        heterocyclyl, heterocyclylalkyl, cycloalkyl, cycloalkylalkyl,        —S(O)_(n2)R¹⁴, -alkylene-S(O)_(n2)—R¹⁵, —COOR¹⁶,        -alkylene-COOR¹⁷, —CONR¹⁸R¹⁹, or -alkylene-CONR²⁰R²¹ (where n2        is 0-2 and R¹⁴-R¹⁸ and R²⁰ are independently hydrogen, alkyl,        haloalkyl, aryl, aralkyl, heteroaryl, heteroaralkyl, cycloalkyl,        cycloalkylalkyl, or heterocyclyl and R¹⁹ and R²¹ are        independently hydrogen or alkyl);

wherein the aromatic or alicyclic ring in the groups attached tocycloalkylene or heterocyclylalkylene is optionally substituted withone, two, or three substituents independently selected from alkyl,haloalkyl, alkoxy, hydroxy, haloalkoxy, halo, carboxy, alkoxycarbonyl,amino, monsubstituted amino, disubstituted amino, or acyl;

R³ is hydrogen or alkyl;

R⁵ is hydrogen or alkyl;

R⁶ is hydrogen, alkyl, haloalkyl, cycloalkyl, aryl, aralkyl, heteroaryl,heteroaralkyl, heterocyclyl, or -alkylene-X²—R²⁵ (wherein X² is —NR²⁶—,—O—, —S(O)_(m)—, —CO—, —COO—, —OCO—, —NR²⁶CO—, —CONR²⁶—, —NR²⁶SO₂—,—SO₂NR²⁶—, —NR²⁶COO—, —OCONR²⁶—, —NR²⁶CONR²⁷—, or —NR²⁶SO₂NR²⁷—, whereR²⁶ and R²⁷ are independently hydrogen, alkyl, or acyl, n4 is 0-2, andR²⁵ is hydrogen, alkyl, haloalkyl, cycloalkyl, cycloalkylalkyl,heterocyclyl, heterocyclylalkyl, aryl, aralkyl, heteroaryl, orheteroaralkyl), wherein said alkylene chain in R⁶ is optionallysubstituted with one to six halo and the aromatic or alicyclic rings inR⁶ are optionally substituted by one, two, or three R^(e) independentlyselected from alkyl, halo, hydroxy, alkoxy, haloalkyl, haloalkoxy, oxo,cyan, nitro, aryl, aryl, aralkyl, heteroaryl, heteroaralkyl,heterocyclyl, cycloalkyl, cycloalkylalkyl, carboxy, or alkoxycarbonyland further where the aromatic or alicyclic rings in R^(e) is optionallysubstituted by one, two or three R^(f) independently selected fromalkyl, alkoxy, haloalkyl, haloalkoxy, halo, hydroxy, carboxy, cyano,nitro, aryl or cycloalkyl;

R⁷ is haloalkyl; and

R⁸ is hydrogen, alkyl, alkoxyalkyl or haloalkyl; or

R⁶ and R⁸ together with the carbon atom to which they are attached formcycloalkylene or heterocyclylalkylene wherein said cycloalkylene isoptionally substituted with one or two substituents independentlyselected from alkyl, haloalkyl, hydroxy, or alkoxy andheterocyclylalkylene is optionally substituted with one or twosubstituents independently selected from alkyl, haloalkyl, hydroxy, oralkoxy;

R²² is hydrogen, fluoro, alkyl, haloalkyl, cycloalkyl, cycloalkylalkyl,heterocyclyl, aryl, aralkyl, heteroaryl, heteroaralkyl, heterocyclyl, orheterocyclylalkyl, wherein the aromatic or alicyclic ring in R²² isoptionally substituted with one, two, or three R^(d) independentlyselected from alkyl, haloalkyl, alkoxy, hydroxy, haloalkoxy, halo,nitro, cyano, carboxy, alkoxycarbonyl, aryl, heteroaryl, cycloalkyl,cycloalkylalkyl, aralkyl, heteroaralkyl, amino, monsubstituted amino,disubstituted amino, or acyl;

Y is -alkylene- or -alkylene-O—, wherein the alkylene group isoptionally substituted with one to six fluoro atoms; and

Z is a direct bond or -alkylene- optionally substituted with one to sixfluoro atoms; or, a pharmaceutically acceptable salt thereof.

A. One representative group of compounds is that of Formula (I) whereinR¹ and R² are hydrogen.

B. Another representative group of compounds is that of Formula (I)wherein R¹ and R² together with the carbon atom to which they areattached form cycloalkylene optionally substituted with one or two R^(b)independently selected from alkyl, halo, dialkylamino, aryl, aralkyl,cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl, alkoxycarbonyl,or aryloxycarbonyl; wherein the aromatic of alicyclic ring in the groupsattached to cycloalkylene is optionally substituted with one, two, orthree substituents independently selected from alkyl, haloalkyl, alkoxy,hydroxy, haloalkoxy, halo, carboxy, alkoxycarbonyl, amino,monsubstituted amino, disubstituted amino, or acyl. In one aspect, R¹and R² together with the carbon atom to which they are attached formcyclopropylene, cyclobutylene, cyclopentylene, or cyclohexyleneoptionally substituted with groups described immediately above. Inanother aspect, R¹ and R² together with the carbon atom to which theyare attached form cyclopropylene, cyclobutylene, cyclopentylene,cyclohexylene, cycloheptylene, 3-benzylcyclopentylene,3-cyclohexylmethylcyclopentylene, 3-cyclopentylmethylcyclopentylene,3-phenylcyclopentylene, 3-cyclohexylcyclopentylene,3-cyclopentylcyclopentylene, 3-pyridin-2-ylmethylcyclopentylene,3-pyridin-3-ylmethylcyclopentylene, 3-pyridin-4-ylmethylcyclopentylene,2-methylcyclopropylene, 2,3-dimethylcyclopropylene,3-benzylcyclobutylene, 3-methylcyclopentylene,3,4-dimethylcyclopentylene, 3-ethylcyclopentylene,3-(1,1-dimethylpropyl)-cyclopentylene, 3-n-butylcyclopentylene,3-ethoxycarbonylcyclopentylene, 3,4-diethoxycarbonyl-cyclopentylene, or3-benzyl-4-dimethylaminocyclopentylene. In a further aspect, R¹ and R²together with the carbon atom to which they are attached formcyclopropylene.

C. Yet another representative group of compounds is that of Formula (I)wherein R¹ and R² together with the carbon atom to which they areattached form heterocyclylalkylene optionally substituted with one tofour R^(e) which are independently selected from alkyl, haloalkyl,hydroxyalkyl, alkoxyalkyl, alkoxyalkyloxyalkyl, aryloxyalkyl,heteroaryloxyalkyl, aminoalkyl, acyl, aryl, aralkyl, heteroaryl,heteroaralkyl, heterocyclyl, heterocyclylalkyl, cycloalkyl,cycloalkylalkyl, —S(O)_(n2)R¹⁴, -alkylene-S(O)_(n2)—R¹⁵, —COOR¹⁶,-alkylene-COOR¹⁷, —CONR¹⁸R¹⁹, or -alkylene-CONR²⁰R²¹ (where n2 is 0-2and R¹⁴-R¹⁸ and R²⁰ are independently hydrogen, alkyl, haloalkyl, aryl,aralkyl, heteroaryl, heteroaralkyl, cycloalkyl, cycloalkylalkyl, orheterocyclyl and R¹⁹ and R²¹ are independently hydrogen or alkyl);wherein the aromatic or alicyclic ring in the groups attached toheterocyclylalkylene is optionally substituted with one, two, or threesubstituents independently selected from alkyl, haloalkyl, alkoxy,hydroxy, haloalkoxy, halo, carboxy, alkoxycarbonyl, amino,monsubstituted amino, disubstituted amino, or acyl. In one aspect, R¹and R² together with the carbon atom to which they are attached formpyrrolidinyl, piperidinyl, tetrahydropyranyl, tetrahydrothiopyranyl,tetrahydrofuranyl, tetrahydrothiopyran-4-yl-1-oxide,tetrahydrothiopyran-4-yl-1,1-dioxide, hexahydropyrimidinyl, orhexahydropyridazinyl optionally substituted as described above. Inanother aspect, R¹ and R² together with the carbon atom to which theyare attached form piperidin-4-yl substituted with one or two alkyl,haloalkyl, aminoalkyl, alkoxycarbonyl, alkoxyalkyl, alkoxyalkyloxyalkyl,heterocyclyl, heterocyclylalkyl, -alkylene-CONR²⁰R²¹, or cycloalkyl. Ina further aspect, R¹ and R² together with the carbon atom to which theyare attached form piperidin-4-yl optionally substituted at the1-position with methyl, ethyl, propyl, n-butyl, n-pentyl,3-dimethylaminopropyl, 4-dimethylaminobutyl, 3-morpholin-4-ylpropyl,3-piperidin-1-yl-propyl, 3-(4-methylpiperazin-1-yl)propyl,3-(1-methylpiperidin-4-yl)propyl, 4-morpholin-4-ylbutyl,2-(2-methoxyethyloxy)ethyl, 4-methoxybutyl, 4-aminocarbonylbutyl,3-aminocarbonylpropyl, morpholin-4-yl, 4-methylpiperazin-1-yl,1-ethoxycarbonylpiperidin-4-yl, 1,1-dioxotetrahydrothiopyran-4-yl,hydroxy, 2,2,2-trifluoroethyl, tert-butyl, 1,2-dimethylpiperidin-4-yl,1,2,6-trimethylpiperidin-4-yl, 1,2,2-trimethylpiperidin-4-yl,1-methyl-2-oxopiperidin-4-yl, 1-methylpiperidin-3-yl,1-tert-butoxycarbonylpiperidin-4-yl, 1-cyclohexylpiperidin-4-yl,1-cyclopropylmethylpyrrolidin-3-yl, 1-benzylpyrrolidin-3-yl,1-benzyloxycarbonylpyrrolidin-3-yl, pyrrolidin-3-yl,1-hydroxypyrrolidin-3-yl, 1-methylpyrrolidin-3-yl,1-ethypyrrolidin-3-yl, 1-n-propyl or n-butylpyrrolidin-3-yl,1-cyclohexylpyrrolidin-3-yl, 1-ethyl-2,2-dimethylpyrrolidin-4-yl,1-propyl-2-methoxycarbonylpiperidin-4-yl, 2-oxopyrrolidin-3-yl,1-ethyl-2-oxopyrrolidin-3-yl, morpholin-4-yl,1-(1-methylpiperidin-4-ylcarbonyl)piperidin-4-yl,1-ethoxycarbonylpiperidin-4-yl, 1-benzylazetidin-3-yl,tetrahydrothiopyran-4-yl-1-oxide, ortetrahydrothiopyran-4-yl-1,1-dioxide. In yet another aspect, R¹ and R²together with the carbon atom to which they are attached formpiperidin-4-yl optionally substituted at the 1-position with methyl,ethyl, propyl, n-butyl, or 2,2,2-trifluoroethyl,tetrahydrothiopyran-4-yl, tetrahydrothiopyran-4-yl-1-oxide,tetrahydrothiopyran-4-yl-1,1-dioxide, or tetrahydropyran-4-yl.

(a) Within the above representative groups (A-C), an illustrative groupof compounds is that wherein R³ and R⁵ are hydrogen; Y is -alkylene-;and Z is a direct bond. In one aspect, Y is methylene or ethylene. Inanother aspect, Y is methylene. Within this illustrative group, oneembodiment of compounds of the invention is that wherein R²² is fluoro,alkyl, aryl, aralkyl, cycloalkyl or cycloalkylalkyl.

(1) Within the above representative and illustrative groups, anexemplary group of compounds is that wherein R⁶ is alkyl, haloalkyl,cycloalkyl, phenyl, benzyl, naphthyl, alkylSO₂alkyl, cycloalkylSO₂alkyl,aryl SO₂alkyl, pyrrolidinyl, piperidinyl, morpholinyl, thiomorpholinyl,piperazinyl, indolinyl, pyranyl, thiopyranyl, furanyl, thienyl,pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyridinyl, isoxazolyl,pyrimidinyl, pyrazinyl, pyridazinyl, indolyl, quinolinyl, benzofuranyl,benzthienyl, benzimidazolyl, benzthiazolyl, benzoisoxazolyl,benzoxazolyl or amino; wherein the aromatic or alicyclic ring in R⁶ isoptionally substituted by one, two, or three R^(e), wherein each R^(e)is independently alkyl, halo; hydroxy, oxo, carboxy, cyano, nitro,cycloalkyl, phenyl, naphthyl, pyrrolidinyl, piperidinyl, morpholinyl,thiomorpholinyl, piperazinyl, furanyl, thienyl, oxazolyl, thiazolyl,imidazolyl, triazolyl, tetrazolyl, pyradinyl, pyrimidinyl, pyrazinyl,indolyl, benzofuranyl, benzothienyl, benzimidazolyl, benzthiazolyl,benzoxazolyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl,alkoxy, —COR (where R is alkyl), alkoxycarbonyl, aryloxycarbonyl wherethe aromatic or alicyclic rings in R^(e) may be further optionallysubstituted by one, two or three R^(f) independently selected fromalkyl, alkoxy, haloalkyl, haloalkoxy, halo, hydroxy, carboxy, cyano,nitro, aryl or cycloalkyl.

In one aspect of the above, R⁶ is methyl, ethyl, isopropyl,trifluoromethyl, cyclopropyl, cyclopentyl, cyclohexyl, phenyl, benzyl,naphthyl, pyrrolidinyl, piperidinyl, morpholinyl, thiomorpholinyl,piperazinyl, furanyl, thienyl, thiazolyl, imidazolyl, pyridinyl, orpyrazinyl wherein the aromatic or alicylic rings in R⁶ are optionallysubstituted with one, two, or three R^(e) independently selected frommethyl, ethyl, fluoro, chloro, bromo, iodo, hydroxy, oxo, carboxy,cyano, nitro, cyclopropyl, phenyl, pyrrolidinyl, piperidinyl,morpholinyl, thiomorpholinyl, piperazinyl, thienyl, imidazolyl, methoxy,acetyl, or methoxycarbonyl, wherein the aromatic or alicyclic rings inR^(e) are further optionally substituted with one, two, or three R^(f)independently selected from methyl, cyclopropyl, phenyl, methoxy,fluoro, chloro, hydroxy, or carboxy. In one embodiment, R⁶ is methyl.

In another aspect of the above, R⁶ is phenyl, naphthyl, pyrrolidinyl,piperidinyl, morpholinyl, thiomorpholinyl, furanyl, thienyl, thiazolyl,imidazolyl, pyridinyl, or pyrazinyl wherein the aromatic or alicyclicrings in R⁶ are optionally substituted with one, two, or three R^(e)independently selected from methyl, fluoro, chloro, phenyl, thienyl,methoxy, acetyl, or methoxycarbonyl. In one embodiment, R⁶ is phenyl,naphthyl, pyrrolidinyl, piperidinyl, furanyl, thienyl, thiazolyl,imidazolyl, pyridinyl, or pyrazinyl wherein the aromatic or alicyclicrings in R⁶ are optionally substituted with one, two, or three R^(e)independently selected from methyl, fluoro, chloro, phenyl, thienyl,methoxy, acetyl, or methoxycarbonyl. In another embodiment, R⁶ isphenyl, 4-methoxyphenyl, 4-chlorophenyl, 4-fluorophenyl, 2-fluorophenyl,2-fluoro-4-chlorophenyl, naphthyl, piperidin-4-yl, furanyl, thienyl,pyridin-4-yl, or pyrazinyl. In a further embodiment, R⁶ is phenyl,4-fluorophenyl, thiophen-2-yl, furan-2-yl, 2-hydroxyphenyl,1-methylpyrrol-2-yl, or indol-3-yl, preferably, phenyl, 4-fluorophenyl,thiophen-2-yl, or furan-2-yl.

(2) Within the above representative and illustrative groups, a furtherexemplary group of compounds is that wherein R⁸ is hydrogen orhaloalkyl, preferably hydrogen or trifluoromethyl. In one embodiment ofthis exemplary group, R⁷ is trifluoromethyl, 2,2,2-trifluoroethyl orpentafluoroethyl, preferably trifluoromethyl; and R⁸ is hydrogen.

(3) Within the above representative and illustrative groups, a furtherexemplary group of compounds is that wherein R⁶ and R⁸ together with thecarbon to which they are attached from cycloalkylene, preferablycyclopentylene, cyclopent-1-enylene, cyclohexylene, cyclohexlenylene. Inone embodiment of this exemplary group, R⁷ is trifluoromethyl,2,2,2-trifluoroethyl or pentafluoroethyl, preferably trifluoromethyl

(4) Within the above representative and illustrative groups, a furtherexemplary, group of compounds is that wherein R⁶ and R⁸ together withthe carbon to which they are attached form heterocyclylalkylene,preferably tetrahydropyran-4-yl or 3,6-dihydro-2H-pyran-4-yl. In oneembodiment of this exemplary group, R⁷ is trifluoromethyl,2,2,2-trifluoroethyl or pentafluoroethyl, preferably trifluoromethyl.

(5) Within the above representative and illustrative groups, a furtherexemplary group of compounds is that wherein R⁶ is phenyl, naphthyl,pyrrolidinyl, piperidinyl, morpholinyl, thiomorpholinyl, furanyl,pyranyl, thienyl, thiazolyl, imidazolyl, pyridinyl, or pyrazinyl whereinthe aromatic or alicyclic rings in R⁶ are optionally substituted withone, two, or three R^(e) independently selected from methyl, fluoro,chloro, phenyl, thienyl, methoxy, acetyl, or methoxycarbonyl. Mostpreferably, R⁶ is phenyl, 4-methoxyphenyl, 4-chlorophenyl,4-fluorophenyl, 2-fluorophenyl, 2-fluoro-4-chlorophenyl, naphthyl,piperidin-4-yl, furanyl, thienyl, pyridin-4-yl, or pyrazinyl. In oneembodiment of this exemplary group, R⁷ is trifluoromethyl,2,2,2-trifluoroethyl or pentafluoroethyl, preferably trifluoromethyl;and R³, R⁵, and R⁸ are hydrogen.

Reference to the embodiments set forth above is meant to include allcombinations of representative, illustrative and exemplary groups unlessstated otherwise.

Compounds of this invention can be made by the methods depicted in thereaction schemes shown below. These schemes are merely illustrative ofsome methods by which the compounds of this invention can besynthesized, and various modifications to these schemes can be made andwill be suggested to one skilled in the art having referred to thisdisclosure.

The starting materials and reagents used in preparing these compoundsare either available from commercial suppliers such as, e.g., AldrichChemical Co., (Milwaukee, Wis.), Bachem (Torrance, Calif.), or Sigma(St. Louis, Mo.), or are prepared by methods known to those skilled inthe art following procedures set forth in references such as Fieser andFieser's Reagents for Organic Synthesis, Volumes 1-17 (John Wiley andSons, 1991); Rodd's Chemistry of Carbon Compounds, Volumes 1-5 andSupplementals (Elsevier Science Publishers, 1989); Organic Reactions,Volumes 1-40 (John Wiley and Sons, 1991), March's Advanced OrganicChemistry, (John Wiley and Sons, 4th Edition) and Larock's ComprehensiveOrganic Transformations (VCH Publishers Inc., 1989).

The starting materials and the intermediates of the reaction may beisolated and purified if desired using conventional techniques,including but not limited to filtration, distillation, crystallization,chromatography and the like. Such materials may be characterized usingconventional means, including physical constants and spectral data.

Unless specified to the contrary, the reactions described herein takeplace at atmospheric pressure over a temperature range from about −78°C. to about 150° C., more preferably from about 0° C. to about 125° C.,and most preferably at about room (or ambient) temperature, e.g., about20° C.

In the reactions described hereinafter, it may be necessary to protectreactive functional groups, for example hydroxy, amino, imino, thio orcarboxy groups, where these are desired in the final product, to avoidtheir unwanted participation in the reactions. Conventional protectinggroups may be used in accordance with standard practice, for examplessee T. W. Greene and P. G. M. Wuts in “Protective Groups in OrganicChemistry” John Wiley and Sons, 1999.

Compounds of Formula (I) where R¹, R², R³, R⁵, R⁶, R⁷, R²², Y and Z areas defined herein and R⁸ is hydrogen can be prepared by proceeding as inthe following Reaction Scheme 1 below.

Reaction of a ketone of formula 1 with an α-amino ester of formula 2where R is a carboxy protecting group, preferably an alkyl group,preferably methyl, under reductive amination reaction conditions providea compound of formula 3. The reaction is carried out in the presence ofa suitable dehydrating agent such as TiCl₄, magnesium sulfate, isopropyltrifluoroacetate, in the presence of a base such asdiisopropylethylamine, pyridine, and the like and in a suitable organicsolvent such as methylene chloride to give an imine. The imine isreduced with a suitable reducing agent such as sodium borohydride,sodium cyanoborohydride, and the like in a suitable organic solvent suchas methanol, ethanol, and the like.

Compound 4 is then reacted with an α-aminoacetonitrile of formula 5 togive a compound of Formula (I). The reaction is typically carried out inthe presence of a suitable coupling agent (such as for example,benzotriazole-1-yloxytrispyrrolidinophosphonium hexafluorophosphate(PyBOP®), O-benzotriazol-1-yl-N,N,N′,N′-tetramethyl-uroniumhexafluorophosphate (EBTU),O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyl-uroniumhexafluorophosphate (HATU),1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (BDC), or1,3-dicyclohexyl-carbodiimide (DCC)), optionally in the presence of1-hydroxybenzotriazole (HOST), and a base such asN,N-diisopropylethylamine, triethylamine, N-methylmorpholine, and thelike. The reaction is typically carried out at about 20 to about 30° C.,preferably at about 25° C., and normally requires about 2 to about 24 hto complete. Suitable reaction solvents are inert organic solvents suchas halogenated organic solvents (e.g., methylene chloride, chloroform,and the like), acetonitrile, N,N-dimethylformamide, ethereal solventssuch as tetrahydrofuran, dioxane, and the like.

Alternatively, the above coupling step can be carried out by firstconverting 4 into an active acid derivative such as succinimide esterand then reacting it with an amine of formula 5. The reaction typicallyrequires about 2 to about 3 h to complete. The conditions utilized inthis reaction depend on the nature of the active acid derivative. Forexample, if it is an acid chloride derivative of 4, the reaction iscarried out in the presence of a suitable base (e.g. triethylamine,diisopropylethylamine, pyridine, and the like). Suitable reactionsolvents are polar organic solvents such as acetonitrile,N,N-dimethylformamide, dichloromethane, or any suitable mixturesthereof.

The above method can also be used to prepare compounds of Formula (I)where R⁸ is other than hydrogen utilizing the procedure described inmethod (i) above, by substituting R⁶COH with a ketone of formula R⁶R⁷COand then treating the resulting intermediate with R⁸Li/R⁸MgX, followedby oxidation to give the free acid. The free acid is then condensed with5 under conditions described above to give compound (I).

It will be apparent to a person skilled in the art, that compounds ofFormula (I) can also be prepared by first condensing 5 with theN-protected amino acid of formula 2 where R is hydrogen, followed byremoval of the amino protecting group and reaction of the free aminocompound with a compound of formula 1 as described in Scheme 1 above.Suitable amino acid protecting groups and reaction conditions forputting them on and removing them can be found in Greene, T. W.; andWuts, P. G. M.; Protecting Groups in Organic Synthesis; John Wiley &Sons, Inc. 1999.

Compounds of formula 1 such as 2,2,2-trifluoromethylacetophenone and2,2,2-trifluoromethyl-4-phenylphenylethanone are commercially available.Others can be prepared by methods well known in the art. α-Amino estersof formula 2 may be commercially available or they can be prepared bymethods well known in the art. For example, compounds of formula 2 canbe prepared as shown below in Method (i).

An α-amino ester of formula 6, where PG is a protecting group (such as,e.g., Boc), is halogenated (formula 7, W═Br, Cl or I) and is thenreacted with a substituted magnesium chloride of formula 8 to give thesubstituted amino ester of formula 9, which in turn is difluorinated byreaction with a source of fluorine atoms, such as for example(diethylamino)sulfur trifluoride (DAST) or Deoxofluor. The resultingdifluoro compound of formula 10 is then deprotected to give the α-aminoester of formula 2 or a salt thereof.

Alternatively, compounds of formula 2 can be prepared as shown below inMethod (ii).

Method (ii)

An α-amino ester of formula 6a, where PG is a protecting group (such as,e.g., Boc), is halogenated (formula 7, L=Br, Cl or I) and is thenreacted with a carboxylic acid derivative of formula 8a to give thesubstituted amino ester of formula 9, which in turn is difluorinated byreaction with a source of fluoro atoms, such as for example(diethylamino)sulfur trifluoride (DAST) or Deoxofluor. The resultingdifluoro compound of formula 10 is then deprotected to give the α-aminoester of formula 2 or a salt thereof.

A compound of Formula (I) can be converted to other compounds of Formula(I). For example:

A compound of Formula (I) where R⁶ is an aromatic ring substituted withhalo can be reacted with appropriate boronic acid-under-palladiumcatalyzed Suzuki coupling reaction conditions to provide a correspondingcompound of Formula (I) where R⁶ is further substituted with an aryl orheteroaryl ring.

A compound of Formula (I) containing a hydroxy group may be prepared bydealkylation/benzylation of an alkoxy/benzyloxy substituent: thosecontaining an acid group, by hydrolysis of an ester group; and thosecontaining a cyano, by displacement of a bromine atom on thecorresponding compounds of Formula (I). A compound of Formula (I)containing a halo group such as chloro can be converted to acorresponding compound of Formula (I) containing an methylthio bytreating it with sodium thiomethoxide. The methylthio group can beoxidized to methylsulfonyl using a suitable oxidizing agent such asOXONE®. A compound of Formula (I) containing a cyano group can beconverted to a corresponding carboxy-containing compound by hydrolysisof the cyano group. The carboxy group, in turn, can be converted to anester group.

A compound of Formula (I) can be prepared as a pharmaceuticallyacceptable acid addition salt by reacting the free base form of thecompound with a pharmaceutically acceptable inorganic or organic acid.Alternatively, a pharmaceutically acceptable base addition salt of acompound of Formula (I) can be prepared by reacting the free acid formof the compound with a pharmaceutically acceptable inorganic or organicbase. Inorganic and organic acids and bases suitable for the preparationof the pharmaceutically acceptable salts of compounds of Formula (I) areset forth in the definitions section of this Application. Alternatively,the salt forms of the compounds of Formula (I) can be prepared usingsalts of the starting materials or intermediates.

The free acid or free base forms of the compounds of Formula (I) can beprepared from the corresponding base addition salt or acid addition saltform. For example, a compound of Formula (I) in an acid addition saltform can be converted to the corresponding free base by treating with asuitable base (e.g., ammonium hydroxide solution, sodium hydroxide, andthe like). A compound of Formula (I) in a base addition salt form can beconverted to the corresponding free acid by treating with a suitableacid (e.g., hydrochloric acid, etc).

The N-oxides of compounds of Formula (I) can be prepared by methodsknown to those of ordinary skill in the art. For example, N-oxides canbe prepared by treating an unoxidized form of the compound of Formula(I) with an oxidizing agent (e.g., trifluoroperacetic acid, permaleicacid, perbenzoic acid, peracetic acid, meta-chloroperoxybenzoic acid, orthe like) in a suitable inert organic solvent (e.g., a halogenatedhydrocarbon such as dichloromethane) at approximately 0° C.Alternatively, the N-oxides of the compounds of Formula (I) can beprepared from the N-oxide of an appropriate starting material.

Compounds of Formula (I) in unoxidized form can be prepared fromN-oxides of compounds of Formula (I) by treating with a reducing agent(e.g., sulfur, sulfur dioxide, triphenyl phosphine, lithium borohydride,sodium borohydride, phosphorus trichloride, tribromide, or the like) inan suitable inert organic solvent (e.g., acetonitrile, ethanol, aqueousdioxane, or the like) at about 0 to about 80° C.

Prodrug derivatives of the compounds of Formula (I) can be prepared bymethods known to those of ordinary skill in the art (e.g., for furtherdetails see Saulnier et al. (1994), Bioorganic and Medicinal ChemistryLetters, Vol. 4, p. 1985). For example, appropriate prodrugs can beprepared by reacting a non-derivatized compound of Formula (I) with asuitable carbamylating agent (e.g., 1,1-acyloxyalkylcarbonochloridate,para-nitrophenyl carbonate, or the like).

Protected derivatives of the compounds of Formula (I) can be made bymeans known to those of ordinary skill in the art. A detaileddescription of the techniques applicable to the creation of protectinggroups and their removal can be found in T. W. Greene, Protecting Groupsin Organic Synthesis, 3^(rd) edition, John Wiley & Sons, Inc. 1999.

Compounds of the present invention may be conveniently prepared orformed during the process of the invention as solvates (e.g. hydrates).Hydrates of compounds of the present invention may be convenientlyprepared by recrystallisation from an aqueous/organic solvent mixture,using organic solvents such as dioxin, tetrahydrofuran or methanol.

Compounds of Formula (I) can be prepared as their individualstereoisomers by reacting a racemic mixture of the compound with anoptically active resolving agent to form a pair of diastereoisomericcompounds, separating the diastereomers and recovering the opticallypure enantiomer. While resolution of enantiomers can be carried outusing covalent diasteromeric derivatives of compounds of Formula (I),dissociable complexes are preferred (e.g., crystalline diastereoisomericsalts). Diastereomers have distinct physical properties (e.g., meltingpoints, boiling points, solubilities, reactivity, etc.) and can bereadily separated by taking advantage of these dissimilarities. Thediastereomers can be separated by chromatography or, preferably, byseparation/resolution techniques based upon differences in solubility.The optically pure enantiomer is then recovered, along with theresolving agent, by any practical means that would not result inracemization. A more detailed description of the techniques applicableto the resolution of stereoisomers of compounds from their racemicmixture can be found in Jean Jacques Andre Collet, Samuel H. Wilen,Enantiomers, Racemates and Resolutions, John Wiley & Sons, Inc. (1981).

In practicing this invention several processes for the generation orpurification of biological agents are used. Methods for preparing thebiologics are well known in the art as discussed below.

Monoclonal antibodies are prepared using standard techniques, well knownin the art, such as by the method of Kohler and Milstein, Nature 1975,256:495, or a modification thereof, such as described by Buck et al.1982, In Vitro 18:377. Typically, a mouse or rat is immunized with theMenB PS derivative conjugated to a protein carrier, boosted and thespleen (and optionally several large lymph nodes) removed anddissociated into single cells. If desired, the spleen cells may bescreened (after removal of non-specifically adherent cells) by applyinga cell suspension to a plate or well coated with the antigen. B-cells,expressing membrane-bound immunoglobulin specific for the antigen, willbind to the plate, and will not be rinsed away with the rest of thesuspension. Resulting B-cells, or all dissociated spleen cells, are theninduced to fuse with myeloma cells to form hybridomas. Representativemurine myeloma lines for use in the hybridizations include thoseavailable from the American Type Culture Collection (ATCC).

Chimeric antibodies composed of human and non-human amino acid sequencesmay be formed from the mouse monoclonal antibody molecules to reducetheir immunogenicity in humans (Winter et al. Nature 1991 349:293;Lobuglio et al. Proc. Nat. Acad. Sci. USA 1989 86:4220; Shaw et al. J.Immunol. 1987 138:4534; and Brown et al. Cancer Res. 1987 47:3577;Riechmann et al. Nature 1988 332:323; Verhoeyen et al. Science 1988239:1534; and Jones et al. Nature 1986 321:522; EP Publication No.519,596, published Dec. 23, 1992; and U.K. Patent Publication No. GB2,276,169, published Sep. 21, 1994).

Antibody molecule fragments, e.g., F(ab′)₂, FV, and sFv molecules, thatare capable of exhibiting immunological binding properties of the parentmonoclonal antibody molecule can be produced using known techniques.Inbar et al. Proc. Nat. Acad. Sci. USA 1972 69:2659; Hochman et al.Biochem. 1976 15:2706; Ehrlich et al. Biochem. 1980 19:4091; Huston etal. Proc. Nat. Acad. Sci. USA 1988 85(16):5879; and U.S. Pat. Nos.5,091,513 and 5,132,405, and U.S. Pat. No. 4,946,778.

In the alternative, a phage-display system can be used to expand themonoclonal antibody molecule populations in vitro. Saiki, et al. Nature1986 324:163; Scharf et al. Science 1986 233:1076; U.S. Pat. Nos.4,683,195 and 4,683,202; Yang et al. J. Mol. Biol. 1995 254:392; Barbas,III et al. Methods: Comp. Meth Enzymol. 1995 8:94; Barbas, III et al.Proc. Natl. Acad. Sci. USA 1991 88:7978.

The coding sequences for the heavy and light chain portions of the Fabmolecules selected from the phage display library can be isolated orsynthesized, and cloned into any suitable vector or replicon forexpression. Any suitable expression system can be used, including, forexample, bacterial, yeast, insect, amphibian and mammalian systems.Expression systems in bacteria include those described in Chang et al.Nature 1978 275:615, Goeddel et al. Nature 1979 281:544, Goeddel et al.Nucleic Acids Res. 1980 8:4057, European Application No. EP 36,776, U.S.Pat. No. 4,551,433, deBoer et al. Proc. Natl. Acad. Sci. USA 198380:21-25, and Siebenlist et al. Cell 1980 20:269.

Expression systems in yeast include those described in Hinnen et al.Proc. Natl. Acad. Sci. USA 1978 75:1929, Ito et al. J. Bacteriol. 1983153:163, Kurtz et al. Mol. Cell. Biol. 1986 6:142, Kunze et al. J. BasicMicrobiol. 1985 25:141, Gleeson et al. J. Gen. Microbiol. 1986 132:3459,Roggenkamp et al. Mol. Gen. Genet. 1986 202:302, Das et al. J.Bacteriol. 1984 158:1165, De Louvencourt et al. J. Bacteriol. 1983154:737, Van den Berg et al. Bio/Technology 1990 8:135, Kunze et al. J.Basic Microbiol. 1985 25:141, Cregg et al. Mol. Cell. Biol. 1985 5:3376,U.S. Pat. Nos. 4,837,148 and 4,929,555, Beach et al. Nature 1981300:706, Davidow et al. Curr. Genet. 1985 10:380, Gaillardin et al.Curr. Genet. 1985 10:49, Ballance et al. Biochem. Biophys. Res. Commun.1983 112:284-289, Tilburn et al. Gene 1983 26:205-221, Yelton et al.Proc. Natl. Acad. Sci. USA 1984 81:1470-1474, Kelly et al. EMBO J. 19854:475479; European Application No. EP 244,234, and InternationalPublication No. WO 91/00357.

Expression of heterologous genes in insects can be accomplished asdescribed in U.S. Pat. No. 4,745,051, European Application Nos. EP127,839 and EP 155,476, Vlak et al, J. Gen. Virol. 1988 69:765-776,Miller et al. Ann. Rev. Microbiol. 1988 42:177, Carbonell et al. Gene1988 73:409, Maeda et al. Nature 1985 315:592-594, Lebacq-Verheyden etal. Mol. Cell. Biol. 1988 8:3129, Smith et al. Proc. Natl. Acad. Sci.USA 1985 82:8404, Miyajima et al. Gene 1987 58:273, and Martin et al.DNA 1988 7:99. Numerous baculoviral strains and variants andcorresponding permissive insect host cells from hosts are described inLuckow et al. Bio/Technology 1988 6:47-55, Miller et al. GENETICENGINEERING, Setlow, J. K. et al. eds., Vol. 8, Plenum Publishing, pp.1986 277-279, and Maeda et al. Nature 1985 315:592-594.

Mammalian expression can be accomplished as described in Dijkema et al.EMBO J. 1985 4:761, Gorman et al. Proc. Natl. Acad. Sci. USA 198279:6777, Boshart et al. Cell 1985 41:521, and U.S. Pat. No. 4,399,216.Other features of mammalian expression can be facilitated as describedin Ham et al. Meth. Enz. 1979 58:44, Barnes et al. Anal. Biochem. 1980102:255, U.S. Pat. Nos. 4,767,704, 4,657,866, 4,927,762, 4,560,655 andReissued U.S. Pat. No. RE 30,985, and in International Publication Nos.WO 90/103430, WO 87/00195. The production of recombinant adenoviralvectors are described in U.S. Pat. No. 6,485,958. Botulinum toxin type Acan be obtained by establishing and growing cultures of Clostridiumbotulinum in a fermenter and then harvesting and purifying the fermentedmixture in accordance with known procedures. Any of the above-describedprotein production methods can be used to provide the biologic thatwould benefit from the present invention.

The compounds of the invention are selective inhibitors of cysteineproteases such as Cathepsin S, K, B, and/or F, and in particularCathepsin S, and accordingly are useful for treating diseases in whichcysteine protease activity contributes to the pathology and/orsymptomatology of the disease. For example, the compounds of theinvention are useful in treating autoimmune disorders, including, butnot limited to, juvenile onset diabetes, psoriasis, multiple sclerosis,pemphigus vulgaris, Graves' disease, myasthenia gravis, systemic lupuserythemotasus, rheumatoid arthritis and Hashimoto's thyroiditis;allergic disorders, including, but not limited to, asthma; andallogeneic immune responses, including, but not limited to, organtransplants or tissue grafts and endometriosis.

Cathepsin S is also implicated in disorders involving excessiveelastolysis, such as chronic obstructive pulmonary disease (e.g.,emphysema), bronchiolitis, excessive airway elastolysis in asthma andbronchitis, pneumonities and cardiovascular disease such as plaquerupture and atheroma. Cathepsin S is implicated in fibril formation and,therefore, inhibitors of Cathepsin S are of use in treatment of systemicamyloidosis.

The cysteine protease inhibitory activities of the compounds of Formula(I) can be determined by methods known to those of ordinary skill in theart. Suitable in vitro assays for measuring protease activity and theinhibition thereof by test compounds are known. Typically, the assaymeasures protease-induced hydrolysis of a peptide-based substrate.

Details of assays for measuring protease inhibitory activity are setforth in Biological Examples 1-5, infra.

In general, compounds of Formula (I) will be administered intherapeutically effective amounts via any of the usual and acceptablemodes known in the art, either singly or in combination with one or moretherapeutic agents. A therapeutically effective amount may vary widelydepending on the severity of the disease, the age and relative health ofthe subject, the potency of the compound used and other factors. Forexample, therapeutically effective amounts of a compound of Formula (I)may range from about 10 micrograms per kilogram body weight (μg/kg) perday to about 100 milligram per kilogram body weight (mg/kg) per day,typically from about 100 μg/kg/day to about 10 mg/kg/day. Therefore, atherapeutically effective amount for an 80 kg human patient may rangefrom about 1 mg/day to about 8 g/day, typically from about 1 mg/day toabout 800 mg/day. In general, one of ordinary skill in the art, actingin reliance upon personal knowledge and the disclosure of thisApplication, will be able to ascertain a therapeutically effectiveamount of a compound of Formula (I) for treating a given disease.

The compounds of Formula (I) can be administered as pharmaceuticalcompositions by one of the following routes: oral, systemic (e.g.,transdermal, intranasal or by suppository) or parenteral (e.g.,intramuscular, intravenous or subcutaneous). Compositions can take theform of tablets, pills, capsules, semisolids, powders, sustained releaseformulations, solutions, suspensions, elixirs, aerosols, or any otherappropriate composition and are comprised of, in general, a compound ofFormula (I) in combination with at least one pharmaceutically acceptableexcipient. Acceptable excipients are non-toxic, aid administration, anddo not adversely affect the therapeutic benefit of the activeingredient. Such excipient may be any solid, liquid, semisolid or, inthe case of an aerosol composition, gaseous excipient that is generallyavailable to one of skill in the art.

Solid pharmaceutical excipients include starch, cellulose, talc,glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silicagel, magnesium stearate, sodium stearate, glycerol monostearate, sodiumchloride, dried skim milk, and the like. Liquid and semisolid excipientsmay be selected from water, ethanol, glycerol, propylene glycol andvarious oils, including those of petroleum, animal, vegetable orsynthetic origin (e.g., peanut oil, soybean oil, mineral oil, sesameoil, and the like). Preferred liquid carriers, particularly forinjectable solutions, include water, saline, aqueous dextrose andglycols.

The amount of a compound of Formula (I) in the composition may varywidely depending upon the type of formulation, size of a unit dosage,kind of excipients and other factors known to those of skill in the artof pharmaceutical sciences. In general, a composition of a compound ofFormula (I) for treating a given disease will comprise from 0.01% w to10% w, preferably 0.3% w to 1% w, of active ingredient with theremainder being the excipient or excipients. Preferably thepharmaceutical composition is administered in a single unit dosage formfor continuous treatment or in a single unit dosage form ad libitum whenrelief of symptoms is specifically required. Representativepharmaceutical formulations containing a compound of Formula (I) aredescribed in the Formulation Examples below.

SYNTHESIS EXAMPLES

The present invention is further exemplified, but not limited by, thefollowing examples that illustrate the preparation of compounds ofFormula (I) and intermediates according to the invention.

Synthesis Example 1 Scheme 1

Scheme 1, Step 1: Synthesis of 1-aminocyclopropanecarbonitrilehydrochloride (1-aminocyclopropanecarbonitrile hydrochloride iscommercially available)

A mixture of benzophenone imine (25 g, 0.138 mol, Aldrich) andaminoacetonitrile hydrochloride (25 g, 0.270 mol, Lancaster) indichloromethane (1000 mL) was stirred in a 2 L Erlenmeyer flask undernitrogen at room temperature for five days. The reaction mixture wasfiltered to remove the precipitated ammonium chloride and the filtratewas evaporated to dryness in vacuo. The resulting residue was dissolvedin ether (400 mL) and washed with water (200 mL) and brine. After dryingover magnesium sulfate, the solution was evaporated to give(benzhydrylideneamino)-acetonitrile (47.89 g).

A solution of sodium hydroxide (91 g, 2.275 mol) in water (91 mL) in a 2L flask was cooled on ice under nitrogen and then treated with benzyltriethyl ammonium chloride (2.0 g, 0.0088 mol, Aldrich) and(benzhydrylideneamino)acetonitrile (47.89 g) in toluene (100 mL).1,2-Dibromoethane (23 mL, 122.4 mmol, Aldrich) was then added dropwise,over 25 min, to the reaction mixture with mechanical stirring andcooling to maintain the internal temperature near +10° C. The reactionmixture was then stirred vigorously for 24 hr at room temperature andthen poured into ice water and extracted with toluene. The combinedextracts were washed with brine and then treated with MgSO₄ and Norite.After filtering, toluene was removed by rotary evaporation to give anoil (67 g). The residue was dissolved in boiling hexane (400 mL),treated with Norite and filtered hot and allowed to cool. A dark oilseparated, which was removed by pipet (˜2 mL). Scratching inducedcrystallization in the remaining solution, which was cooled on ice for 2hr. Light yellow crystals were collected by filtration and washed withcold hexane to give 1-(benzhydrylideneamino)-cyclopropanecarbonitrile(30.56 g).

A mixture of 1-(benzhydrylideneamino)cyclopropanecarbonitrile (30.56 g,0.124 mol) in concentrated HCl (12 mL) in water (100 mL) and ether (100mL) was stirred at room temperature for 15 hr. The ether layer wasdiscarded and the aqueous layer was washed with ether. The aqueous layerwas then freeze-dried to give 1-aminocyclopropanecarbonitrilehydrochloride as a tan powder (13.51 g). Analytical data is consistantwith published data.

Synthesis Example 2 Scheme 2

Scheme 2, Step 1: Synthesis of (S)-methyl2-(benzyloxycarbonylamino)-4-chloro-4-oxobutanoate

See, Synth. Comm. 1993, 23(18): 2511-2526. 2-MethylN-carbobenzoxy-L-aspartate (5 g, 17.7 mmol) was dissolved in 30 mL ofdry THF and stirred under N₂ at 0° C. Thionyl chloride (10.5 g, 88.5mmol, 5 eq.) was added to the solution by syringe at 0° C., and thesolution was refluxed for one hr. The solvent was removed in vacuo andthe product was crystallized by methylene chloride/hexane to give2(S)-2-benzyloxycarbonylamino-3-chlorocarbonylpropionic acid methylester. ¹H NMR (400 MHz, CDCl₃) δ 3.48 (dd, 1H, J=18.5 Hz, J=3.7 Hz),3.56 (dd, 1H, J=18.5 Hz, J=3.7 Hz), 3.74 (s, 3H), 4.58 (m, 1H), 5.10 (s,2H), 5.72 (d, 1H), 7.30-7.35 (m, 5H) ppm.

Scheme 2, Step 2: (S)-methyl2-(benzyloxycarbonylamino)-4-oxo-5-phenylpentanoate

To a suspension of copper(I) bromide-dimethyl sulfide complex (2.6 g,12.72 mmol, 1.2 eq.) in dry THF was added a solution of lithium bromide(2.2 g, 25.44 mmol, 2.4 eq.) in dry THF. The mixture was stirred at roomtemperature (RT) for 20 min, and then was cooled to −78° C. A solutionof benzyl magnesium chloride (13 mL, 12.72 mmol, 1.2 eq.) followed by asolution of (S)-methyl2-(benzyloxycarbonylamino)-4-chloro-4-oxobutanoate (3.16 g, 10.6 mmol, 1eq.) in dry THF were added. The mixture was stirred at −78° C. for 30min and then was quenched with sat. ammonium chloride. The mixture wasextracted with ethyl acetate. The organic layers were dried overmagnesium sulfate and then concentrated in vacuo. The residue waspurified by flash column (1:1 ethyl acetate:hexane) to give 2 g of(S)-methyl 2-(benzyloxycarbonylamino)-4-oxo-5-phenylpentanoate.

Scheme 2, Step 3: (S)-methyl2-(benzyloxycarbonylamino)-4,4-difluoro-5-phenylpentanoate

A mixture of (S)-methyl2-(benzyloxycarbonylamino)-4-oxo-5-phenylpentanoate (2 g) and(diethylamino)sulfur trifluoride (DAST) (5 g) was stirred at RT overthree days. The mixture was then diluted with dichloromethane (100 mL)and carefully added to 0.5N NaOH solution (150 mL). The aqueous layerwas extracted with methylene chloride. The organic layers were driedover magnesium sulfate and were then concentrated in vacuo. The residuewas purified by flash column (1:4-1:3 ethyl acetate:hexane) to give(S)-methyl 2-(benzyloxycarbonylamino)-4,4-difluoro-5-phenylpentanoate.¹H-NMR (CDCl₃) δ 7.2-7.4 (4H, m), 5.4 (1H), 5.05 (2H), 4.6 (1H), 3.7(3H), 3.15 (2H), 2.3 (2H). ¹⁹F-NMR (CDCl₃) δ −95 ppm.

Scheme 2, Step 4: (S)-Methyl 2-amino-4,4-difluoro-5-phenylpentanoatehydrobromide

A mixture of (S)-methyl2-(benzyloxycarbonylamino)-4,4-difluoro-5-phenylpentanoate (188 mg, 0.5mmol) and hydrogen bromide (2 mL) was stirred at RT for two hr, afterwhich the solvent was removed to give the title (S)-methyl2-amino-4,4-difluoro-5-phenylpentanoate hydrobromide.

Synthesis Example 3 Synthesis of Other Amino Acid Methyl Ester HBr SaltsVia Chemistry Analogous to Scheme 2

Following the procedure of Synthesis Example 2 above,2-benzyloxycarbonylamino-3-chlorocarbonylpropionic acid methyl ester isreacted with the appropriate substituted magnesium chloride startingmaterials in the presence of Cu⁺ to prepare the HBr salts of thefollowing amino acid methyl esters:

(S)-methyl 2-amino-4,4-difluoro-4-phenylbutanoate hydrobromide

(S)-methyl 2-(benzyloxycarbonylamino)-4,4-difluoro-4-phenylbutanoate:¹H-NMR (CDCl₃) δ 7.2-7.4 (4H, m), 5.4 (1H), 5.05 (2H), 4.6 (1H), 3.7(3H), 3.15 (2H), 2.3 (2H). ¹⁹F-NMR (CDCl₃) δ −95 ppm.

(S)-methyl 2-amino-4,4-difluoro-6-methylheptanoate hydrobromide

(S)-methyl 2-(benzyloxycarbonylamino)-4,4-difluoro-6-methylheptanoate:¹H-NMR (CDCl₃) δ 7.3-7.4 (5H, m), 5.55 (d), 5.2 (s), 4.6 (m), 3.8 (s),2.3-2.5 (m), 1.65-2.0 (m). ¹⁹F-NMR (CDCl₃) δ −94 ppm

(S)-methyl 2-amino-4,4-difluorohexanoate hydrobromide

Following the procedure of Synthesis Example 2, (S)-methyl2-(benzyloxycarbonylamino)-4-oxohexanoate was prepared from ethylmagnesium chloride (6 mL, 12 mmol), Cu⁺ and (S)-methyl2-(benzyloxycarbonylamino)-4-chloro-4-oxobutanoate (3 g, 10 mmol).

(S)-methyl 2-(benzyloxycarbonylamino)-4-oxohexanoate (0.6 g, 2.04 mmol,1 eq.) and Deoxyfluor (50% in toluene (Agros); 2.8 g, 1.7 mmol, 5 eq.)were combined in a nalgene container and ethanol (30 μL) was added. Themixture was stirred at RT overnight, followed by heating at 35° C. for45 min., to give (S)-methyl2-(benzyloxycarbonylamino)-4,4-difluorohexanoate. See, Synthesis 2002,17: 2561-2578. ¹H-NMR (CDCl₃) δ 7.9 (1H, d), 7.2-7.4 (5H, m), 4.2-4.3(1H, m), 5.05 (s, 214), 4.3 (1H, m), 3.65 (3H, m), 2.2-2.4 (2H, m),1.8-2.0 (2H, m), 0.9 (3H, m); ¹⁹F-NMR (CDCl₃) δ −97.5 (dd) ppm

Following the procedure of Synthesis Example 2, a mixture of (S)-methyl2-(benzyloxycarbonylamino)-4,4-difluorohexanoate and hydrogen bromidewere reacted together to give (S)-methyl 2-amino-4,4-difluorohexanoatehydrobromide.

(S)-methyl 2-amino-4,4-difluorooctanoate hydrobromide: Following theprocedure of Synthesis Example 2, (S)-methyl2-(benzyloxycarbonylamino)-4-oxooctanoate was prepared from n-butylmagnesium chloride, Cu⁺ and (S)-methyl2-(benzyloxycarbonylamino)-4-chloro-4-oxobutanoate.

(S)-methyl 2-amino-4,4-difluoroheptanoate hydrobromide: Following theprocedure of Synthesis Example 2, (S)-methyl2-(benzyloxycarbonylamino)-4-heptanoate was prepared from n-butylmagnesium chloride, Cu⁺ and (S)-methyl2-(benzyloxycarbonylamino)-4-chloro-4-oxobutanoate.

(S)-methyl 2-(benzyloxycarbonylamino)-4,4-difluoroheptanoate: ¹H-NMR(CDCl₃) δ 7.9 (d), 7.2-7.4 (5H, m), 5.0 (3H, s), 4.3 (1H, m), 3.6 (s,3H), 2.2-2.5 (m), 1.7-1.9 (m), 1.4-1.9 (m), 0.7-0.9 (m); ¹⁹F-NMR (CDCl₃)δ −95 ppm.

(S)-methyl 2-amino-4-cyclopentyl-4,4-difluorobutanoate

(S)-methyl 2-amino-4-cyclohexyl-4,4-difluorobutanoate

Synthesis Example 4 Scheme 3

Scheme 3, Step 1: (S)-methyl2-(benzyloxycarbonylamino)-5-cyclopropyl-4-oxopentanoate

Zinc dust (785 mg, 12 mmol) was heated under vacuum for 5 min. and thenallowed to cool to RT. The flask was purged with dry N₂ (2×). Dry phenol(12 mL) and dry DMA (0.8 mL) were added to the flask and the mixture waswarmed to about 50° C. with vigorous stirring. 1,2-Dibromoethane (14 μL)was added and the mixture was then allowed to cool to RT and stirred for30 min., after which TMSCl was added. The mixture was stirred at RT foranother 30 min, after which R-benzyloxycarbonylamino-3-iodopropionicacid methyl ester (981 mg, 3 mmol) was added. After about 90 min.,palladium catalyst (such as PdCl₂(PPh₃)₂) and cyclopropylmethylcarbonylchloride (3 mmol) were added and the reaction was stirred for another 45min., to give 520 mg of (S)-methyl2-(benzyloxycarbonylamino)-5-cyclopropyl-4-oxopentanoate. ¹H-NMR (500MHz, CDCl₃): 7.36 (5H, m, Ar—H), 5.79 (1H, bs, NH), 5.14 (2H, S, 2H),4.59 (1H, m, NCH), 3.78 (3H, s, OMe), 3.18 (2H, dd, CH₂), 2.29 (2H, m,CH₂), 0.92 (1H, m, CH), 0.59 (2H, m, CH₂), 0.16 (2H, m, CH₂).

EIMS (m/z): 320.14 (M⁺+1)

Scheme 3, Step 2: (S)-methyl2-(benzyloxycarbonylamino)-5-cyclopropyl-4,4-difluoropentanoate

A mixture of (S)-methyl2-(benzyloxycarbonylamino)-5-cyclopropyl-4-oxopentanoate (285 mg, 1mmol) and DAST (0.92 mL, 5 mmol) was stirred at RT in a sealed tube for48 hr. The mixture was then diluted with methylene chloride and quenchedwith sat. NaHCO₃ (9.2 μL), after which it was partitioned between CH₂Cl₂and sat. NaHCO₃. The CH₂Cl₂ extracts were dried and concentrated invacuo, and the residue was purified by flash chromatography(1:4-hexane:ethanol) to give 100 mg of (S)-methyl2-(benzyloxycarbonylamino)-5-cyclopropyl-4,4-difluoropentanoate as acolorless oil. ¹H-NMR (500 MHz, CDCl₃): 7.38 (5H, m, Ar—H), 5.49 (1H,bs, NH), 5.18 (2H, S, 2H), 4.61 (1H, m, NCH), 3.78 (3H, s, OMe), 2.52(2H, m, CH₂), 1.80 (2H, m, CH₂), 0.82 (1H, m, CH), 0.59 (2H, m, CH₂),0.16 (2H, m, CH₂). EIMS (m/z): 342.12 (M⁺+1).

Scheme 3, Step 3: (S)-Methyl2-amino-5-cyclopropyl-4,4-difluoropentanoate hydrochloride

A solution of (S)-methyl2-(benzyloxycarbonylamino)-5-cyclopropyl-4,4-difluoropentanoate (570 mg,1.87 mmol) in dioxane/4N-HCl (9 mL, 37 mmol) was stirred at RT for twohr, after which the solvent was removed by rotoevaporation to give 450mg of (S)-methyl 2-amino-5-cyclopropyl-4,4-difluoropentanoatehydrochloride as a beige solid.

Synthesis Example 4 Scheme 4

Scheme 4, Step 1: (S)-methyl 2-(boc-amino)-5-chloro-5-oxopentanoate

A mixture of(S)-5-tert-butoxy-4-(tert-butoxycarbonylamino)-5-oxopentanoic acid (3.03g, 10 mmol) and methoxymethylamine HCl (1.17 g, 12 mmol) in HOBt (1.62g, 12 mmol), EDC (2.3 g, 12 mmol) and NMM (3.3 mL, 30 mmol) was stirredat RT for 2 hr. The reaction was washed with 1N-HCl, NaHCO₃ and sat.NaCl and dried over MgSO₄. The solvent was removed to give 3.67 g of(S)-tert-butyl3,11,11-trimethyl-4,9-dioxo-2,10-dioxa-3,8-diazadodecane-7-carboxylate,as a colorless oil. See, Syn. Lett. 2003, 10: 1411-1414.

Scheme 4, Step 2: (S)-tert-butyl2-(tert-butoxycarbonylamino)-5-oxoheptanoate

The above butanoic acid ester ((S)-tert-butyl3,11,11-trimethyl-4,9-dioxo-2,10-dioxa-3,8-diazadodecane-7-carboxylate)(1.38 g, 4 mmol) was dissolved in THF and cooled to −40° C., after whichethyl magnesium chloride (5 mL, 10 mmol) was added. The reaction mixturewas stirred at −40° C. for 1 hr. 1N HCl was then added, and the crudeproduct was extracted with EtOAc and purified by flash column (20%EtOAc-hexane) to give (S)-tert-butyl2-(tert-butoxycarbonylamino)-5-oxoheptanoate.

Scheme 4, Step 3: (S)-tert-butyl2-(tert-butoxycarbonylamino)-5,5-difluoroheptanoate

Following the procedure of Synthesis Example 2, Scheme 2, Step 3,(S)-tert-butyl 2-(tert-butoxycarbonylamino)-5-oxoheptanoate (1 g) andDeoxyfluor (5 mL) were reacted together in the presence of catalyticamount of ethanol to give (5)-tert-butyl2-(tert-butoxycarbonylamino)-5,5-difluoroheptanoate.

Scheme 4, Step 4: (S)-methyl 2-amino-5,5-difluoroheptanoate TFA salt

(S)-tert-butyl 2-(tert-butoxycarbonylamino)-5,5-difluoroheptanoate (1mmol) and TFA (5 mL) were stirred together at RT for 1 hr. The solventwas then removed and diethyl ether was added to precipitate out thesolid, which was then filtered to give(S)-methyl2-amino-5,5-difluoroheptanoate TFA salt.

The (S)-methyl 2-amino-5,5-difluoroheptanoate TFA salt (1 mmol) wasdissolved in methanol (5 mL) and benzene (5 mL), after whichTMS-diazomethane (2.0M in hexane; 3 mL) was added and the mixturestirred at RT for 10 min. The solvent was removed and HCl in dioxane wasadded, after which solvent was again removed. Diethyl ether was added toprecipitate out the solid, which was then filtered to give(S)-methyl2-amino-5,5-difluoroheptanoate hydrochloride.

Synthesis Example 5 Synthesis of Other Amino Acid Methyl Esters

Following the procedure of Synthesis Example 4, Scheme 4 above, thefollowing amino acid methyl esters are prepared from the appropriatestarting materials:

(S)-methyl 2-amino-5-cyclopropyl-5,5-difluoropentanoate

(S)-methyl 2-amino-5,5-difluoro-5-phenylpentanoate

(S)-methyl 2-amino-5,5-difluoro-6-phenylhexanoate

Synthesis Example 6 Scheme 5

Scheme 5, Step 1:(S)-4,4-difluoro-5-phenyl-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)pentanoicacid

Methyl (S)-methyl 2-amino-4,4-difluoro-5-phenylpentanoate HBr salt (2.44mmol, 1 eq.) was dissolved in dry methanol. Trifluoromethyl4-fluorophenyl ketone (2.44 mmol, 1 eq.) and potassium carbonate (4.88mmol, 2 eq.) were added, and the mixture was heated at 50° C. overnight.To the resulting condensation (imine-formation) reaction product wasadded, at −30° C., a suspension of Zn(BH₄)₂ (ca. 1.1 eq.) [which wasprepared from NaBH₄ (1 eq.) and ZnCl₂ (1M in diethyl ether; 2 eq.)], andthe mixture was allowed to warm to RT overnight. The reaction wasquenched with 1 N HCl and extracts with ethyl acetate, dried andconcentrated to give the crude product,(S)-4,4-difluoro-5-phenyl-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)pentanoicacid

Scheme 5, Step 2:(S)—N-(1-cyanocyclopropyl)-4,4-difluoro-5-phenyl-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)pentanamide

A mixture of the above pentanoic acid(S)-4,4-difluoro-5-phenyl-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)pentanoicacid, (1 mmol), 1-aminocyclopropanecarbonitrile hydrochloride (1.2mmol), HATU (1.2 mmol) and NMM (4.0 mmol), in DMF, was stirred at RT for2 hr. Saturated ammonium chloride and ethyl acetate were then added, andthe reaction was stirred an additional 20 min at RT, after which productwas extracted with ethyl acetate, purified with flash column (30-35%ethyl acetate-hexane), and crystallized with DCM-hexane to give(S)—N-(1-cyanocyclopropyl)-4,4-difluoro-5-phenyl-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)pentanamideas a white crystal. ¹H-NMR (CDCl₃) δ 8.9 (1H), 7.2-7.5 (9H, m), 4.33(1H, m), 3.2-3.5 (3H), 2.0-2.6 (2H), 1.6-1.8 (2H), 0.75 (1H), 0.58 (1H).¹⁹F-NMR (CDCl₃) δ −113 ppm. LC/EIMS (m/z): 470 (M+Na)+.

Synthesis Example 7 Synthesis of Acid Amides of the Invention

In like manner as in Synthesis Example 6, the following amides areprepared from reaction of 1-aminocyclopropanecarbonitrile hydrochloridewith the appropriate carboxylic acid derived from the correspondingdifluoroamino acid ester:

(S)—N-(1-cyanocyclopropyl)-4,4-difluoro-4-phenyl-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)butanamide

(S)—N-(1-cyanocyclopropyl)-4,4-difluoro-6-methyl-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)heptanamide

¹H-NMR (CDCl₃) δ 7.4 (2H, m), 7.38-7.42 (2H, m), 6.9 (1H, s), 4.2-4.3(1H, m), 3.2-3.55 (m), 1.9-2.5 (m), 1.75-1.9 (m), 0.9-1.1 (m). ¹⁹F-NMR(CDCl₃) δ −74.5 (s), −94, −112 (s) ppm. LC/EIMS (m/z): 436 (M+H)⁺

(S)—N-(1-cyanocyclopropyl)-5-cyclopropyl-4,4-difluoro-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)pentanamide

¹H-NMR (CDCl₃) δ 7.45 (1H, s), 7.30-7.35 (2H, m), 7.05-7.15 (2H, m),4.2-4.3 (1H, m), 3.4-3.5 (1H, m), 2.2-2.6 (3H, m), 1.7-1.9 (2H, m),1.5-1.6 (m), 1.0-1.3 (2H, m), 0.7-0.9 (1H, m), 0.5-0.6 (2H, m), 0.1-0.2(2H, m) ¹⁹F-NMR (CDCl₃) δ −74.8 (s), −95.4, −111.5 (s) ppm. LC/EIMS(m/z): 434 (M+H)⁺

(S)—N-(1-cyanocyclopropyl)-4,4-difluoro-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)hexanamide

¹H-NMR (CDCl₃) δ 7.5 (1H, s), 7.38-7.42 (2H, m), 7.1-7.2 (2H, m),4.2-4.3 (1H, m), 3.45-3.50 (1H, m), 2.2-2.5 (m), 1.8-2.0 (m), 1.0-1.2(m) ¹⁹F-NMR (CDCl₃) δ −74.5 (s), −98.5 (dd), −111 (s) ppm. LC/EIMS(m/z): 408 (M+H)⁺

(S)—N-(1-cyanocyclopropyl)-4,4-difluoro-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)heptanamide

¹H-NMR (d₆-DMSO) δ 8.9 (s), 7.2-7.5 (m), 7.2-7.3 (m), 4.3-4.4 (1H, m),3.2-3.5 (m), 2.0-2.3 (2H, m), 1.3-1.4 (m), 0.9-0.8 (1H, m), 0.4-0.5 (1H,m); ¹⁹F-NMR (CDCl₃) δ −73.1 (s), −98.0, −113.2 (s) ppm. LC/EIMS (m/z):421.9 (M+H)⁺

(S)—N-(1-cyanocyclopropyl)-4,4-difluoro-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)octanamide

(S)—N-(1-cyanocyclopropyl)-4-cyclopropyl-4,4-difluoro-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)butanamide

(S)—N-(1-cyanocyclopropyl)-4-cyclohexyl-4,4-difluoro-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)butanamide

(S)—N-(1-cyanocyclopropyl)-5,5-difluoro-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)heptanamide

¹H-NMR (d₆-DMSO) δ 8.9 (s), 7.2-7.5 (m), 7.2-7.3 (m), 4.3-4.4 (1H, m),3.2-3.5 (m), 2.0-2.3 (2H, m), 1.3-1.4 (m), 0.9-0.8 (1H, m), 0.4-0.5 (1H,m); ¹⁹F-NMR (CDCl₃) δ −73.1 (s), −98.0, −113.2 (s) ppm. LC/EIMS (m/z):421 (M+H)⁺ Rt=6.01 min.

(S)—N-(1-cyanocyclopropyl)-5-cyclopropyl-5,5-difluoro-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)pentanamide

(S)—N-(1-cyanocyclopropyl)-5,5-difluoro-5-phenyl-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)pentanamide

(S)—N-(1-cyanocyclopropyl)-5,5-difluoro-6-phenyl-2-((S)-2,2,2-trifluoro-1-(4-fluorophenyl)ethylamino)hexanamide

Synthesis Example 8 Scheme 6

In a manner analogous to the chemistry described in Synthesis Example 6,Scheme additional analogs were synthesized by varying the substitutionon the phenyl ring of 2,2,2-trifluoro-1-phenylethanone.

Scheme 6, Step 1:(S)-5-cyclopropyl-4,4-difluoro-2-((S)-2,2,2-trifluoro-1-phenylethylamino)pentanoicacid

(S)-5-cyclopropyl-4,4-difluoro-1-methoxy-1-oxopentan-2-aminehydrochloride (250 mg, 10 mmol), trifluoroacetophenone (179 mg, 10mmol), potassium carbonate (426 mg, 30 mmol) was charged in isopropanol(10 mL) under nitrogen. The reaction mixture stirred for 20 h at 60° C.When TLC showed an absence of starting material, is the mixture wasfiltered under hot and the solids were washed with isopropanol (20 mL)and the filtrates were combined and concentrated under reduced pressure.The residue (400 mg, 10 mmol) was dissolved in acetonitrile (5 mL) andmethanol (1 mL) and transferred to a dropping funnel under nitrogen. Thezinc borohydride suspension prepared as described above was cooled to−45° C. and treated with the imine solution which was added drop-wiseand the reaction was stirred at same temperature for 1 h. Once thestaring material was consumed, is the reaction mixture was quenched with1N HCl solution (10 mL) at 0° C. and then allowed to warm to roomtemperature. The mixture was extracted with ethyl acetate (3×40 mL) andthe combined organic extracts washed with water (50 mL) and brine (50mL). The organic extracts were evaporated under reduced pressure, andthe residue re-dissolved in ethyl acetate (20 mL) and washed with water(20 mL) and brine (50 mL). The solution was dried (MgSO₄) and thesolvent evaporated under reduced pressure to give(S)-5-cyclopropyl-4,4-difluoro-2-((S)-2,2,2-trifluoro-1-phenylethylamino)pentanoicacid as a pale oil (265 mg, 71.3%).

Preparation of Zinc Borohydride: Zinc chloride (1.0 g, 7.3 mmol) wassuspended in 1,2-DME (10 mL) under nitrogen and stirred for 1 h at roomtemperature. The resulting white slurry was cooled to ˜5° C. and treatedin portions with sodium borohydride (550 mg, 14 mmol). The ice bath wasremoved and the mixture was stirred at room temperature for 24 h to givea light grey suspension of Zn(BH₄)₂.

Scheme 6, Step 2:(S)—N-(1-cyanocyclopropyl)-5-cyclopropyl-4,4-difluoro-2-((S)-2,2,2-trifluoro-1-phenylethylamino)pentanamide

A stirred solution of(S)-5-cyclopropyl-4,4-difluoro-2-((S)-2,2,2-trifluoro-1-phenylethylamino)pentanoicacid (150 mg, 0.4 mmol) in DMF (15 mL) was treated with HATU (253 mg,0.5 mmol) and DIPEA (0.3 mL, 1.7 mL mmol). After 15 min,1-cyanocyclopropane hydrochloride (61 mg, 0.5 mmol) was added and thereaction mixture was stirred under a nitrogen atmosphere for 2 h. Oncethe reaction was complete, the reaction mixture was quenched withsaturated sodium bicarbonate solution, extracted with ethyl acetate &washed with 1HCl solution and brine, dried over Na₂SO₄, filtered and wasconcentrated. The crude compound was purified by silica gel columnchromatography eluting with 10% ethyl acetate in hexane followed byre-crystallization from DCM and pentane to provide(S)—N-(1-cyanocyclopropyl)-5-cyclopropyl-4,4-difluoro-2-((S)-2,2,2-trifluoro-1-phenylethylamino)pentanamide(65 mg, 37%) as white solid. ¹H-NMR (500 MHz, DMSO-d₆): 8.88 (1H, s,NH), 7.38 (5H, s, Ar—H), 4.23 (1H, m, CHCF₃), 3.39 (1H, m, CH), 3.18(1H, m, NH), 2.23 (2H, m, CH₂), 1.94 (2H, m, CH₂), 1.32 (2H, m, CH₂),0.82 (2H, m, CH₂), 0.57 (1H, m, CH), 0.45 (2H, m, CH₂), 0.12 (2H, m,CH₂). ¹⁹F-NMR (500 MHz, CD₃OD): −74.609 (CF₂), −95.308, −95.507 (CF₃).EIMS (m/z): 416 (M+H)¹. HPLC: 97.37% (RT 16.39) Column used zorbax SB,C8, 250×4.6 mm, 5 uMobile Phase: ACN (B): 0.1% TFA in water (A) Flowrate: 1.0 mL/Min

Synthesis Example 9 Synthesis of Acid Amides of the Invention

In like manner as in Synthesis Example 8, the following amides areprepared from reaction of 1-aminocyclopropanecarbonitrile hydrochloridewith the appropriate carboxylic acid derived from the correspondingdifluoroamino acid ester:

(S)—N-(1-cyanocyclopropyl)-5-cyclopropyl-4,4-difluoro-2-((S)-2,2,2-trifluoro-1-(4-methoxyphenyl)ethylamino)pentanamide

¹H-NMR (500 MHz, CD₃OD): 7.28, 6.93 (4H, A₂B₂, Ar—H), 4.18 (1H, m,CHCF₃), 3.79 (3H, s, OMe), 3.42 (1H, m, CH), 2.33 (2H, m, CH₂), 1.84(2H, m, CH₂), 1.38 (2H, m, CH₂), 1.01 (1H, m, CH), 0.82 (2H, m, CH₂),0.53 (2H, m, CH₂), 0.19 (2H, m, CH₂). ¹³C-NMR (500 MHz, CD₃OD): 176.90(1C, CO), 161.85 (1C, ArC-OMe), 130.95 (2C, ArC), 127.64 (1C, ArC),125.78 (1C, CF₃), 120.97 (1C, CN), 115.17 (2C, ArC), 97.26 (2C, CF₂),64.17 (1C, q, CCF₃), 57.49 (1C, OCH₃), 55.79 (1C, CHN), 42.81 (1C, t,CCF₂), 40.50 (1C, t, CCF₂), 21.02 (1C, C), 16.83, 16.65 (2C, CH₂), 5.53(1C, CCH), 4.60, 4.52 (2C, CH₂) ¹⁹F-NMR (500 MHz, CD₃OD): −74.609,−74.940 (CF₂), −95.308, −95.606 (CF₃). EIMS (m/z): 446 (M+H)¹. HPLC:98.95% (RT 16.41) Column used zorbax SB, C8, 250×4.6 mm, 5 u. MobilePhase: ACN (A): 0.1% TFA in water (B). Flow rate: 1.5 mL/Min

(S)—N-(1-cyanocyclopropyl)-5-cyclopropyl-2-((S)-1-(3,4-difluorophenyl)-2,2,2-trifluoroethylamino)-4,4-difluoropentanamide

¹H-NMR (500 MHz, CD₃OD): 7.42-7.21 (3H, m, Ar—H), 4.25 (1H, m, CHCF₃),3.42 (1H, m, CH), 2.37 (2H, m, CH₂), 1.83 (2H, m, CH₂), 1.41 (2H, m,CH₂), 0.99 (2H, m, CH₂), 0.82 (1H, m, CH), 0.57 (2H, m, CH₂), 0.19 (2H,m, CH₂). ¹⁹F-NMR (500 MHz, CD₃OD): −74.808 (CF₂), −95.308, −95.705(CF₃), −135.646, −135.844 (2×Ar—F). EIMS (m/z): 452 (M+H)¹. HPLC: 94.12%(RT 16.70) Column used zorbax SB, C8, 250×4.6 mm, 5 u Mobile Phase: ACN(A): 0.1% TFA in water (B) Flow rate: 1.5 mL/Min

(S)—N-(1-cyanocyclopropyl)-5-cyclopropyl-4,4-difluoro-2-((S)-2,2,2-trifluoro-1-(4-(trifluoromethyl)phenyl)ethylamino)pentanamide

¹H-NMR (500 MHz, CD₃OD): 7.76, 7.62 (4H, A₂B₂, Ar—H), 4.38 (1H, m,CHCF₃), 3.52 (1H, m, CH), 2.38 (2H, m, CH₂), 1.83 (2H, m, CH₂), 1.40(2H, m, CH₂), 1.02 (1H, m, CH), 0.82 (2H, m, CH₂), 0.53 (2H, m, CH₂),0.19 (2H, m, CH₂). ¹⁹F-NMR (500 MHz, CD₃OD): EIMS (m/z): 484 (M+HPLC:93.13% (RT 17.14) Column used zorbax SB, C8, 250×4.6 mm, 5 u MobilePhase: ACN (A): 0.1% TFA in water (B) Flow rate: 1.5 mL/Min

BIOLOGICAL EXAMPLES Biological Example 1 Cathepsin B Assay

Solutions of test compounds in varying concentrations were prepared in10 μL of dimethyl sulfoxide (DMSO) and then diluted into assay buffer(40 μL, comprising: N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid(BES), 50 mM (pH 6); polyoxyethylenesorbitan monolaurate, 0.05%; anddithiothreitol (DTT), 2.5 mM). Human cathepsin B (0.025 pMoles in 25 μLof assay buffer) was added to the dilutions. The assay solutions weremixed for 5-10 seconds on a shaker plate, covered and incubated for 30min at room temperature. Z-FR-AMC (20 nMoles in 25 μL of assay buffer)was added to the assay solutions and hydrolysis was followedspectrophotometrically at (λ460 nm) for 5 min. Apparent inhibitionconstants (K_(i)) were calculated from the enzyme progress curves usingstandard mathematical models.

Compounds of the invention were tested by the above-described assay andobserved to exhibit cathepsin B inhibitory activity.

Biological Example 2 Cathepsin K Assay

Solutions of test compounds in varying concentrations were prepared in10 μL of dimethyl sulfoxide (DMSO) and then diluted into assay buffer(40 μL, comprising: MES, 50 mM (pH 5.5); EDTA, 2.5 mM; and DTT, 2.5 mM).Human cathepsin K (0.0906 pMoles in 25 μL of assay buffer) was added tothe dilutions. The assay solutions were mixed for 5-10 seconds on ashaker plate, covered and incubated for 30 min at room temperature.Z-Phe-Arg-AMC (4 nMoles in 25 μL of assay buffer) was added to the assaysolutions and hydrolysis was followed spectrophotometrically at (λ460nm) for 5 min. Apparent inhibition constants (K_(i)) were calculatedfrom the enzyme progress curves using standard mathematical models.

Compounds of the invention were tested by the above-described assay andobserved to exhibit cathepsin K inhibitory activity.

Biological Example 3 Cathepsin L Assay

Solutions of test compounds in varying concentrations were prepared in10 μL of dimethyl sulfoxide (DMSO) and then diluted into assay buffer(40 mL, comprising: MES, 50 mM (pH 5.5); EDTA, 2.5 mM; and DTT, 2.5 mM).Human cathepsin L (0.05 pMoles in 25 μL of assay buffer) was added tothe dilutions. The assay solutions were mixed for 5-10 seconds on ashaker plate, covered and incubated for 30 min at room temperature.Z-Phe-Arg-AMC (1 nMoles in 25 μL of assay buffer) was added to the assaysolutions and hydrolysis was followed spectrophotometrically at (λ460nm) for 5 min. Apparent inhibition constants (K_(i)) were calculatedfrom the enzyme progress curves using standard mathematical models.

Compounds of the invention were tested by the above-described assay andobserved to exhibit cathepsin L inhibitory activity.

Biological Example 4 Cathepsin S Assay

Solutions of test compounds in varying concentrations were prepared in10 μL of dimethyl sulfoxide (DMSO) and then diluted into assay buffer(40 μL, comprising: MES, 50 mM (pH 6.5); EDTA, 2.5 mM; and NaCl, 100mM); β-mercaptoethanol, 2.5 mM; and BSA, 0.00%. Human cathepsin S (0.05pMoles in 25 μL of assay buffer) was added to the dilutions. The assaysolutions were mixed for 5-10 seconds on a shaker plate, covered andincubated for 30 min at room temperature. Z-Val-Val-Arg-AMC (4 nMoles in25 μL, of assay buffer containing 10% DMSO) was added to the assaysolutions and hydrolysis was followed spectrophotometrically (at λ 460nm) for 5 min. Apparent inhibition constants (K_(i)) were calculatedfrom the enzyme progress curves using standard mathematical models.

Compounds of the invention were tested by the above-described assay andobserved to exhibit cathepsin S inhibitory activity.

Biological Example 5 Cathepsin F Assay

Solutions of test compounds in varying concentrations were prepared in10 μL of dimethyl sulfoxide (DMSO) and then diluted into assay buffer(40 μL, comprising: MES, 50 mM (pH 6.5); EDTA, 2.5 mM; and NaCl, 100mM); DTT, 2.5 mM; and BSA, 0.01%. Human cathepsin F (0.1 pMoles in 25μl, of assay buffer) was added to the dilutions. The assay solutionswere mixed for 5-10 seconds on a shaker plate, covered and incubated for30 min at room temperature. Z-Phe-Arg-AMC (2 nMoles in 25 μL of assaybuffer containing 10% DMSO) was added to the assay solutions andhydrolysis was followed spectrophotometrically (at λ460 nm) for 5 min.Apparent inhibition constants (K_(i)) were calculated from the enzymeprogress curves using standard mathematical models.

Compounds of the invention were tested by the above-described assay andobserved to exhibit cathepsin F inhibitory activity. Representative datafor the assays above is provided in the Table below.

Table of Cathepsin Activity Cathepsin S Cathepsin F Cat K- Cathepsin LCathepsin B Compound (K_(i)) (K_(i)) HURAB (K_(i)) (K_(i)) (K_(i))

(++++) (++) (++) (+++) (+++)

(++++) (+) (++) (++) (+)

(++++) (+++) (+++) (+++) (+++)

(++++) (+++) (+++) (+++) (+++)

(++++) (+++) (++++) (+++) (+++)

(++++) (+++) (+++) (+++) (+++)

(++++)

(++++) Activity legend: K_(i) < 20 nM(++++); K_(i) 21-500 nM(+++); K_(i)500 nM-5 uM(++); K_(i) > 5 uM (+)

PHARMACEUTICAL FORMULATION EXAMPLES Representative pharmaceuticalformulations Containing a Compound of Formula (I) Formulation Example 1Oral Formulation

Compound of Formula (I) 10-100 mg Citric Acid Monohydrate 105 mg SodiumHydroxide  18 mg Flavoring Water q.s. to 100 mL

Formulation Example 2 Intravenous Formulation

Compound of Formula (I) 0.1-10 mg Dextrose Monohydrate q.s. to makeisotonic Citric Acid Monohydrate 1.05 mg Sodium Hydroxide 0.18 mg Waterfor Injection q.s. to 1.0 mL

Formulation Example 3 Tablet Formulation

Compound of Formula (I)  1% Microcrystalline Cellulose 73% Stearic Acid25% Colloidal Silica  1%

The foregoing invention has been described in some detail by way ofillustration and example, for purposes of clarity and understanding. Itwill be obvious to one of skill in the art that changes andmodifications may be practiced within the scope of the appended claims.Therefore, it is to be understood that the above description is intendedto be illustrative and not restrictive. The scope of the inventionshould, therefore, be determined not with reference to the abovedescription, but should instead be determined with reference to thefollowing appended claims, along with the full scope of equivalents towhich such claims are entitled.

What is claimed is:
 1. A compound having the following structure:

or a pharmaceutically acceptable salt thereof.